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A frequent side comment has been to remove the use of writel_relaxed,
readl_relaxed, and mb. This reduces driver complexity and the _relaxed
variants were not known to provide any noticeable performance benefit.
Signed-off-by: Ryan Case <[email protected]>
Reviewed-by: Evan Green <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Most RX/TX-specific DMA functions are prefixed with "sci_dma_[rt]x_".
Rename the exceptions to increase consistency.
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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When submitting a DMA request fails in sci_dma_rx_complete(), the driver
tries to fall back to PIO, but that does not work: no more data will be
received, or the kernel will even crash.
Fix this similar as in (but not identical to) sci_submit_rx():
- On SCIF, PIO cannot take over if any DMA transactions are pending,
hence they must be terminated first.
- All active cookies must be invalidated, else rx_timer_fn() may
trigger a NULL pointer dereference.
- Restarting the port is not needed, as it is already running, but
serial port interrupts must be directed back from the DMA engine to
the CPU.
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Extract the functionality to direct new serial port interrupts back to
the CPU into its own helper, to prepare for using it from a second
callsite.
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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The cookies and channel pointer for the DMA receive channel are
invalidated in two places, and one more is planned.
Extract this functionality in a common helper.
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct foo {
int stuff;
void *entry[];
};
instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct foo {
int stuff;
void *entry[];
};
instance = devm_kzalloc(dev, sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = devm_kzalloc(dev, struct_size(instance, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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spi_register_driver() may fail, so let's pass its return value upstream.
Signed-off-by: Kangjie Lu <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Since board support for the CLPS711X platform was removed
(commit 4a56f46a7dc6 ("ARM: clps711x: Remove boards support")),
remove the board support from the driver.
Signed-off-by: Alexander Shiyan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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The ltq_r32() and ltq_w32() macros use the __raw_readl() and
__raw_writel() functions which do not swap the value to little endian.
On the big endian vrx200 SoC the UART is operated in big endian IO mode,
the readl() and write() functions convert the value to little endian
first and then the driver does not work any more on this SoC.
Currently the vrx200 SoC selects the CONFIG_SWAP_IO_SPACE option,
without this option the serial driver would work, but PCI devices do not
work any more.
This patch makes the driver use the __raw_readl() and __raw_writel()
functions which do not swap the endianness. On big endian system it is
assumed that the device should be access in big endian IO mode and on a
little endian system it would be access in little endian mode.
Fixes: 89b8bd2082bb ("serial: lantiq: Use readl/writel instead of ltq_r32/ltq_w32")
Signed-off-by: Hauke Mehrtens <[email protected]>
Acked-by: John Crispin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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The commit a9ddb575d6d6
("dmaengine: dw_dmac: Enhance device tree support")
introduces is_private property in uncertain understanding what does it mean.
First of all, documentation defines DMA_PRIVATE capability as
Documentation/crypto/async-tx-api.txt:
The DMA_PRIVATE capability flag is used to tag dma devices that should not be
used by the general-purpose allocator. It can be set at initialization time
if it is known that a channel will always be private. Alternatively,
it is set when dma_request_channel() finds an unused "public" channel.
A couple caveats to note when implementing a driver and consumer:
1/ Once a channel has been privately allocated it will no longer be
considered by the general-purpose allocator even after a call to
dma_release_channel().
2/ Since capabilities are specified at the device level a dma_device with
multiple channels will either have all channels public, or all channels
private.
Documentation/driver-api/dmaengine/provider.rst:
- DMA_PRIVATE
The devices only supports slave transfers, and as such isn't available
for async transfers.
The capability had been introduced by the commit 59b5ec21446b
("dmaengine: introduce dma_request_channel and private channels")
and some code didn't changed from that times ever.
Taking into consideration above and the fact that on all known platforms
Synopsys DesignWare DMA engine is attached to serve slave transfers,
the DMA_PRIVATE capability must be enabled for this device unconditionally.
Otherwise, as rightfully noticed in drivers/dma/at_xdmac.c:
/*
* Without DMA_PRIVATE the driver is not able to allocate more than
* one channel, second allocation fails in private_candidate.
*/
because of of a caveats mentioned in above documentation excerpts.
So, remove conditional around DMA_PRIVATE followed by removal leftovers.
If someone wonders, DMA_PRIVATE can be not used if and only if the all channels
of the DMA controller are supposed to serve memory-to-memory like operations.
For example, EP93xx has two controllers, one of which can only perform
memory-to-memory transfers
Note, this change doesn't affect dmatest to be able to test such controllers.
Cc: Greg Kroah-Hartman <[email protected]> (maintainer:SERIAL DRIVERS)
Cc: Dan Williams <[email protected]>
Signed-off-by: Andy Shevchenko <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Vinod Koul <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull more ARM SoC updates from Olof Johansson:
"A few updates that we merged late but are low risk for regressions for
other platforms (and a few other straggling patches):
- I mis-tagged the 'drivers' branch, and missed 3 patches. Merged in
here. They're for a driver for the PL353 SRAM controller and a
build fix for the qualcomm scm driver.
- A new platform, RDA Micro RDA8810PL (Cortex-A5 w/ integrated
Vivante GPU, 256MB RAM, Wifi). This includes some acked
platform-specific drivers (serial, etc). This also include DTs for
two boards with this SoC, OrangePi 2G and OrangePi i86.
- i.MX8 is another new platform (NXP, 4x Cortex-A53 + Cortex-M4, 4K
video playback offload). This is the first i.MX 64-bit SoC.
- Some minor updates to Samsung boards (adding a few peripherals in
DTs).
- Small rework for SMP bootup on STi platforms.
- A couple of TEE driver fixes.
- A couple of new config options (bcm2835 thermal, Uniphier MDMAC)
enabled in defconfigs"
* tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (27 commits)
ARM: multi_v7_defconfig: enable CONFIG_UNIPHIER_MDMAC
arm64: defconfig: Re-enable bcm2835-thermal driver
MAINTAINERS: Add entry for RDA Micro SoC architecture
tty: serial: Add RDA8810PL UART driver
ARM: dts: rda8810pl: Add interrupt support for UART
dt-bindings: serial: Document RDA Micro UART
ARM: dts: rda8810pl: Add timer support
ARM: dts: Add devicetree for OrangePi i96 board
ARM: dts: Add devicetree for OrangePi 2G IoT board
ARM: dts: Add devicetree for RDA8810PL SoC
ARM: Prepare RDA8810PL SoC
dt-bindings: arm: Document RDA8810PL and reference boards
dt-bindings: Add RDA Micro vendor prefix
ARM: sti: remove pen_release and boot_lock
arm64: dts: exynos: Add Bluetooth chip to TM2(e) boards
arm64: dts: imx8mq-evk: enable watchdog
arm64: dts: imx8mq: add watchdog devices
MAINTAINERS: add i.MX8 DT path to i.MX architecture
arm64: add support for i.MX8M EVK board
arm64: add basic DTS for i.MX8MQ
...
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Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.
It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.
A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.
This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.
There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)
- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.
Signed-off-by: Linus Torvalds <[email protected]>
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Add UART driver for RDA Micro RDA8810PL SoC.
Signed-off-by: Andreas Färber <[email protected]>
Signed-off-by: Manivannan Sadhasivam <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Olof Johansson <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver updates from Greg KH:
"Here is the large TTY/Serial driver set of patches for 4.21-rc1.
A number of small serial driver changes along with some good tty core
fixes for long-reported issues with locking. There is also a new
console font added to the tree, for high-res screens, so that should
be helpful for many.
The last patch in the series is a revert of an older one in the tree,
it came late but it resolves a reported issue that linux-next was
having for some people.
Full details are in the shortlog, and all of these, with the exception
of the revert, have been in linux-next for a while with no reported
issues"
* tag 'tty-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (85 commits)
Revert "serial: 8250: Default SERIAL_OF_PLATFORM to SERIAL_8250"
serial: sccnxp: Allow to use non-standard baud rates
serial: sccnxp: Adds a delay between sequential read/write cycles
tty: serial: qcom_geni_serial: Fix UART hang
tty: serial: qcom_geni_serial: Fix wrap around of TX buffer
serial: max310x: Fix tx_empty() callback
dt-bindings: serial: sh-sci: Document r8a774c0 bindings
dt-bindings: serial: sh-sci: Document r8a774a1 bindings
Fonts: New Terminus large console font
dt-bindings: serial: lpuart: add imx8qxp compatible string
serial: uartps: Fix interrupt mask issue to handle the RX interrupts properly
serial: uartps: Fix error path when alloc failed
serial: uartps: Check if the device is a console
serial: uartps: Add the device_init_wakeup
tty: serial: samsung: Increase maximum baudrate
tty: serial: samsung: Properly set flags in autoCTS mode
tty: Use of_node_name_{eq,prefix} for node name comparisons
tty/serial: do not free trasnmit buffer page under port lock
serial: 8250: Rate limit serial port rx interrupts during input overruns
dt-bindings: serial: 8250: Add rate limit for serial port input overruns
...
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git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit updates from Paul Moore:
"In the finest of holiday of traditions, I have a number of gifts to
share today. While most of them are re-gifts from others, unlike the
typical re-gift, these are things you will want in and around your
tree; I promise.
This pull request is perhaps a bit larger than our typical PR, but
most of it comes from Jan's rework of audit's fanotify code; a very
welcome improvement. We ran this through our normal regression tests,
as well as some newly created stress tests and everything looks good.
Richard added a few patches, mostly cleaning up a few things and and
shortening some of the audit records that we send to userspace; a
change the userspace folks are quite happy about.
Finally YueHaibing and I kick in a few patches to simplify things a
bit and make the code less prone to errors.
Lastly, I want to say thanks one more time to everyone who has
contributed patches, testing, and code reviews for the audit subsystem
over the past year. The project is what it is due to your help and
contributions - thank you"
* tag 'audit-pr-20181224' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: (22 commits)
audit: remove duplicated include from audit.c
audit: shorten PATH cap values when zero
audit: use current whenever possible
audit: minimize our use of audit_log_format()
audit: remove WATCH and TREE config options
audit: use session_info helper
audit: localize audit_log_session_info prototype
audit: Use 'mark' name for fsnotify_mark variables
audit: Replace chunk attached to mark instead of replacing mark
audit: Simplify locking around untag_chunk()
audit: Drop all unused chunk nodes during deletion
audit: Guarantee forward progress of chunk untagging
audit: Allocate fsnotify mark independently of chunk
audit: Provide helper for dropping mark's chunk reference
audit: Remove pointless check in insert_hash()
audit: Factor out chunk replacement code
audit: Make hash table insertion safe against concurrent lookups
audit: Embed key into chunk
audit: Fix possible tagging failures
audit: Fix possible spurious -ENOSPC error
...
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This reverts commit 6d11023c345e369bcb9d5a68b271764e362c1f6e.
It causes issues with Guenter's test systems and since there seems to
not be any agreement about _why_ this is a problem, but reverting it
fixes things, let's revert until the root cause is found.
Reported-by: Guenter Roeck <[email protected]>
Cc: Florian Fainelli <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Pull sparc fixes from David Miller:
"Just some small fixes here and there, and a refcount leak in a serial
driver, nothing serious"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
serial/sunsu: fix refcount leak
sparc: Set "ARCH: sunxx" information on the same line
sparc: vdso: Drop implicit common-page-size linker flag
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The function of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
su_get_type() doesn't do that. The match node are used as an identifier
to compare against the current node, so we can directly drop the refcount
after getting the node from the path as it is not used as pointer.
Fix this by use a single variable and drop the refcount right after
of_find_node_by_path().
Signed-off-by: Yangtao Li <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
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This patch adds support for the use of non-standard baud rates.
For these purposes, we use the built-in timer/counter.
Signed-off-by: Alexander Shiyan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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This patch adds a delay between sequential read/write cycles,
to ensure the required minimum inactive time (tRWD). A time value
from the datasheet has been added for each type of supported chips.
The “inline” compiler attribute has been removed from the
read/write functions, simply allow the compiler to control this.
Signed-off-by: Alexander Shiyan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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If a serial console write occured while a UART transmit command was
waiting for a done signal then no further data would be sent until
something new kicked the system into gear. If there is already data
waiting in the circular buffer we must re-enable the tx watermark so we
receive the expected interrupts.
Signed-off-by: Ryan Case <[email protected]>
Reviewed-by: Evan Green <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Before commit a1fee899e5bed ("tty: serial: qcom_geni_serial: Fix
softlock") the size of TX transfers was limited to the TX FIFO size,
and wrap arounds of the UART circular buffer were split into two
transfers. With the commit wrap around are allowed within a transfer.
The TX FIFO of the geni serial port uses a word size of 4 bytes. In
case of a circular buffer wrap within a transfer the driver currently
may write an incomplete word to the FIFO, with some bytes containing
data from the circular buffer and others being zero. Since the
transfer isn't completed yet the zero bytes are sent as if they were
actual data.
Handle wrap arounds of the TX buffer properly and ensure that words
written to the TX FIFO always contain valid data (unless the transfer
is completed).
Fixes: a1fee899e5bed ("tty: serial: qcom_geni_serial: Fix softlock")
Signed-off-by: Matthias Kaehlcke <[email protected]>
Reviewed-by: Evan Green <[email protected]>
Tested-by: Ryan Case <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Function max310x_tx_empty() accesses the IRQSTS register, which is
cleared by IC when reading, so if there is an interrupt status, we
will lose it. This patch implement the transmitter check only by
the current FIFO level.
Signed-off-by: Alexander Shiyan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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This patch Correct the RX interrupt mask value to handle the
RX interrupts properly.
Fixes: c8dbdc842d30 ("serial: xuartps: Rewrite the interrupt handling logic")
Signed-off-by: Nava kishore Manne <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Michal Simek <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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When cdns_uart_console allocation failed there is a need to also clear
ID from ID list.
Fixes: ae1cca3fa347 ("serial: uartps: Change uart ID port allocation")
Signed-off-by: Michal Simek <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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While checking for console_suspend_enabled also check if the
device is a console.
Signed-off-by: Shubhrajyoti Datta <[email protected]>
Signed-off-by: Michal Simek <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Initialise the device wakeup.
The device_init_wakeup is needed for the wakeup to work by default.
Uart can be configured as the primary wakeup source so it is good to
enable wakeup by default.
The same functionality is enabled also by 8250_omap, atmel_serial,
omap-serial and stm32-usart.
Signed-off-by: Shubhrajyoti Datta <[email protected]>
Signed-off-by: Michal Simek <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Commit f6aa5beb45be ("serial: 8250: Fix clearing FIFOs in RS485 mode
again") makes a change to FIFO clearing code which its commit message
suggests was intended to be specific to use with RS485 mode, however:
1) The change made does not just affect __do_stop_tx_rs485(), it also
affects other uses of serial8250_clear_fifos() including paths for
starting up, shutting down or auto-configuring a port regardless of
whether it's an RS485 port or not.
2) It makes the assumption that resetting the FIFOs is a no-op when
FIFOs are disabled, and as such it checks for this case & explicitly
avoids setting the FIFO reset bits when the FIFO enable bit is
clear. A reading of the PC16550D manual would suggest that this is
OK since the FIFO should automatically be reset if it is later
enabled, but we support many 16550-compatible devices and have never
required this auto-reset behaviour for at least the whole git era.
Starting to rely on it now seems risky, offers no benefit, and
indeed breaks at least the Ingenic JZ4780's UARTs which reads
garbage when the RX FIFO is enabled if we don't explicitly reset it.
3) By only resetting the FIFOs if they're enabled, the behaviour of
serial8250_do_startup() during boot now depends on what the value of
FCR is before the 8250 driver is probed. This in itself seems
questionable and leaves us with FCR=0 & no FIFO reset if the UART
was used by 8250_early, otherwise it depends upon what the
bootloader left behind.
4) Although the naming of serial8250_clear_fifos() may be unclear, it
is clear that callers of it expect that it will disable FIFOs. Both
serial8250_do_startup() & serial8250_do_shutdown() contain comments
to that effect, and other callers explicitly re-enable the FIFOs
after calling serial8250_clear_fifos(). The premise of that patch
that disabling the FIFOs is incorrect therefore seems wrong.
For these reasons, this reverts commit f6aa5beb45be ("serial: 8250: Fix
clearing FIFOs in RS485 mode again").
Signed-off-by: Paul Burton <[email protected]>
Fixes: f6aa5beb45be ("serial: 8250: Fix clearing FIFOs in RS485 mode again").
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Daniel Jedrychowski <[email protected]>
Cc: Marek Vasut <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: stable <[email protected]> # 4.10+
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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This driver can be used to communicate with Bluetooth chip in high-speed
UART mode, so increase the maximum baudrate to 3Mbps.
Signed-off-by: Seung-Woo Kim <[email protected]>
[mszyprow: rephrased commit message]
Signed-off-by: Marek Szyprowski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Commit 391f93f2ec9f ("serial: core: Rework hw-assited flow control support")
has changed the way the autoCTS mode is handled.
According to that change, serial drivers which enable H/W autoCTS mode must
set UPSTAT_AUTOCTS to prevent the serial core from inadvertently disabling
TX. This patch adds proper handling of UPSTAT_AUTOCTS flag.
Signed-off-by: Beomho Seo <[email protected]>
[mszyprow: rephrased commit message]
Signed-off-by: Marek Szyprowski <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Convert string compares of DT node names to use of_node_name_eq helper
instead. This removes direct access to the node name pointer.
For hvc, the code can also be simplified by using of_stdout pointer
instead of searching again for the stdout node.
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Rob Herring <[email protected]>
Acked-by: Michael Ellerman <[email protected]>
Acked-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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LKP has hit yet another circular locking dependency between uart
console drivers and debugobjects [1]:
CPU0 CPU1
rhltable_init()
__init_work()
debug_object_init
uart_shutdown() /* db->lock */
/* uart_port->lock */ debug_print_object()
free_page() printk()
call_console_drivers()
debug_check_no_obj_freed() /* uart_port->lock */
/* db->lock */
debug_print_object()
So there are two dependency chains:
uart_port->lock -> db->lock
And
db->lock -> uart_port->lock
This particular circular locking dependency can be addressed in several
ways:
a) One way would be to move debug_print_object() out of db->lock scope
and, thus, break the db->lock -> uart_port->lock chain.
b) Another one would be to free() transmit buffer page out of db->lock
in UART code; which is what this patch does.
It makes sense to apply a) and b) independently: there are too many things
going on behind free(), none of which depend on uart_port->lock.
The patch fixes transmit buffer page free() in uart_shutdown() and,
additionally, in uart_port_startup() (as was suggested by Dmitry Safonov).
[1] https://lore.kernel.org/lkml/20181211091154.GL23332@shao2-debian/T/#u
Signed-off-by: Sergey Senozhatsky <[email protected]>
Reviewed-by: Petr Mladek <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Waiman Long <[email protected]>
Cc: Dmitry Safonov <[email protected]>
Cc: Steven Rostedt <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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When a serial port gets faulty or gets flooded with inputs, its interrupt
handler starts to work double time to get the characters to the workqueue
for the tty layer to handle them. When this busy time on the serial/tty
subsystem happens during boot, where it is also busy on the userspace
trying to initialise, some processes can continuously get preempted
and will be on hold until the interrupts subside.
The fix is to backoff on processing received characters for a specified
amount of time when an input overrun is seen (received a new character
before the previous one is processed). This only stops receive and will
continue to transmit characters to serial port. After the backoff period
is done, it receive will be re-enabled. This is optional and will only
be enabled by setting 'overrun-throttle-ms' in the dts.
Signed-off-by: Darwin Dingel <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Disable M_TX_FIFO_WATERMARK_EN after we've sent all data for a given
transaction so we don't continue to receive a flurry of free space
interrupts while waiting for the M_CMD_DONE notification. Re-enable the
watermark when establishing the next transaction.
Also clear the watermark interrupt after filling the FIFO so we do not
receive notification again prior to actually having free space.
Signed-off-by: Ryan Case <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Tested-by: Douglas Anderson <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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On (H)SCIF, sci_submit_rx() is called in the receive interrupt handler.
Hence if DMA submission fails, the interrupt handler should resume
handling reception using PIO, else no more data is received.
Make sci_submit_rx() return an error indicator, so the receive interrupt
handler can act appropriately.
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Acked-by: Wolfram Sang <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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When falling back to PIO, active_rx must be set to a different value
than cookie_rx[i], else sci_dma_rx_find_active() will incorrectly find a
match, leading to a NULL pointer dereference in rx_timer_fn() later.
Use zero instead, which is the same value as after driver
initialization.
Signed-off-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Some callers of sci_submit_rx() hold the port spinlock, others don't.
During fallback to PIO, the driver needs to obtain the port spinlock.
If the lock was already held, spinlock recursion is detected, causing a
deadlock: BUG: spinlock recursion on CPU#0.
Fix this by adding a flag parameter to sci_submit_rx() for the caller to
indicate the port spinlock is already held, so spinlock recursion can be
avoided.
Move the spin_lock_irqsave() up, so all DMA disable steps are protected,
which is safe as the recently introduced dmaengine_terminate_async() can
be called in atomic context.
Signed-off-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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We want the TTY changes in here as well.
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty driver fixes from Greg KH:
"Here are three small tty driver fixes for 4.20-rc6
Nothing major, just some bug fixes for reported issues. Full details
are in the shortlog.
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var()
tty: serial: 8250_mtk: always resume the device in probe.
tty: do not set TTY_IO_ERROR flag if console port
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
"Here are some small USB fixes for 4.20-rc6
The "largest" here are some xhci fixes for reported issues. Also here
is a USB core fix, some quirk additions, and a usb-serial fix which
required the export of one of the tty layer's functions to prevent
code duplication. The tty maintainer agreed with this change.
All of these have been in linux-next with no reported issues"
* tag 'usb-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
xhci: Prevent U1/U2 link pm states if exit latency is too long
xhci: workaround CSS timeout on AMD SNPS 3.0 xHC
USB: check usb_get_extra_descriptor for proper size
USB: serial: console: fix reported terminal settings
usb: quirk: add no-LPM quirk on SanDisk Ultra Flair device
USB: Fix invalid-free bug in port_over_current_notify()
usb: appledisplay: Add 27" Apple Cinema Display
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This patch is trying to fix KE issue due to
"BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198"
reported by Syzkaller scan."
[26364:syz-executor0][name:report8t]BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198
[26364:syz-executor0][name:report&]Read of size 1 at addr ffffff900e44f95f by task syz-executor0/26364
[26364:syz-executor0][name:report&]
[26364:syz-executor0]CPU: 7 PID: 26364 Comm: syz-executor0 Tainted: G W 0
[26364:syz-executor0]Call trace:
[26364:syz-executor0][<ffffff9008095cf8>] dump_bacIctrace+Ox0/0x470
[26364:syz-executor0][<ffffff9008096de0>] show_stack+0x20/0x30
[26364:syz-executor0][<ffffff90089cc9c8>] dump_stack+Oxd8/0x128
[26364:syz-executor0][<ffffff90084edb38>] print_address_description +0x80/0x4a8
[26364:syz-executor0][<ffffff90084ee270>] kasan_report+Ox178/0x390
[26364:syz-executor0][<ffffff90084ee4a0>] _asan_report_loadi_noabort+Ox18/0x20
[26364:syz-executor0][<ffffff9008b092ac>] param_set_kgdboc_var+Ox194/0x198
[26364:syz-executor0][<ffffff900813af64>] param_attr_store+Ox14c/0x270
[26364:syz-executor0][<ffffff90081394c8>] module_attr_store+0x60/0x90
[26364:syz-executor0][<ffffff90086690c0>] sysfs_kl_write+Ox100/0x158
[26364:syz-executor0][<ffffff9008666d84>] kernfs_fop_write+0x27c/0x3a8
[26364:syz-executor0][<ffffff9008508264>] do_loop_readv_writev+0x114/0x1b0
[26364:syz-executor0][<ffffff9008509ac8>] do_readv_writev+0x4f8/0x5e0
[26364:syz-executor0][<ffffff9008509ce4>] vfs_writev+0x7c/Oxb8
[26364:syz-executor0][<ffffff900850ba64>] SyS_writev+Oxcc/0x208
[26364:syz-executor0][<ffffff90080883f0>] elO_svc_naked +0x24/0x28
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:report&]The buggy address belongs to the variable:
[26364:syz-executor0][name:report&] kgdb_tty_line+Ox3f/0x40
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:report&]Memory state around the buggy address:
[26364:syz-executor0] ffffff900e44f800: 00 00 00 00 00 04 fa fa fa fa fa fa 00 fa fa fa
[26364:syz-executor0] ffffff900e44f880: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa
[26364:syz-executor0]> ffffff900e44f900: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00
[26364:syz-executor0][name:report&] ^
[26364:syz-executor0] ffffff900e44f980: 00 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa
[26364:syz-executor0] ffffff900e44fa00: 04 fa fa fa fa fa fa fa 00 fa fa fa fa fa fa fa
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:panic&]Disabling lock debugging due to kernel taint
[26364:syz-executor0]------------[cut here]------------
After checking the source code, we've found there might be an out-of-bounds
access to "config[len - 1]" array when the variable "len" is zero.
Signed-off-by: Macpaul Lin <[email protected]>
Acked-by: Daniel Thompson <[email protected]>
Cc: stable <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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This reverts commit eca42d4cf3c591c36312c52707e0a712e0c7256a.
During review it was rejected, so drop it from the tree.
Cc: Rajan Vaja <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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It seems like when ldsem_down_read() fails with timeout, it misses
update for sem->wait_readers. By that reason, when writer finally
releases write end of the semaphore __ldsem_wake_readers() does adjust
sem->count with wrong value:
sem->wait_readers * (LDSEM_ACTIVE_BIAS - LDSEM_WAIT_BIAS)
I.e, if update comes with 1 missed wait_readers decrement, sem->count
will be 0x100000001 which means that there is active reader and it'll
make any further writer to fail in acquiring the semaphore.
It looks like, this is a dead-code, because ldsem_down_read() is never
called with timeout different than MAX_SCHEDULE_TIMEOUT, so it might be
worth to delete timeout parameter and error path fall-back..
Cc: Jiri Slaby <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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Make sure under CONFIG_LOCKDEP that each change to line discipline
is done with held write semaphor.
Otherwise potential reader will have a good time dereferencing
incomplete/uninitialized ldisc.
An exception here is tty_ldisc_open(), as it's called without ldisc_sem
locked by tty_init_dev() => tty_ldisc_setup() for the tty->link.
It seem valid as tty_init_dev() will call tty_driver_install_tty()
which will find ops->install(). Install will establish tty->link in
pty_common_install(), just after allocation of slave tty with
alloc_tty_struct(). So, no one should have a reference to slave pty yet.
Cc: Jiri Slaby <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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For some reason ldsem has its own lockdep wrappers, make them go away.
Cc: Jiri Slaby <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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As notted by Jiri, tty_ldisc_reinit() shouldn't rely on tty counter.
Simplify math by increasing the counter after reinit success.
Cc: Jiri Slaby <[email protected]>
Link: lkml.kernel.org/r/<[email protected]>
Suggested-by: Jiri Slaby <[email protected]>
Reviewed-by: Jiri Slaby <[email protected]>
Tested-by: Mark Rutland <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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There might be situations where tty_ldisc_lock() has blocked, but there
is already IO on tty and it prevents line discipline changes.
It might theoretically turn into dead-lock.
Basically, provide more priority to pending tty_ldisc_lock() than to
servicing reads/writes over tty.
User-visible issue was reported by Mikulas where on pa-risc with
Debian 5 reboot took either 80 seconds, 3 minutes or 3:25 after proper
locking in tty_reopen().
Cc: Jiri Slaby <[email protected]>
Reported-by: Mikulas Patocka <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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tty_ldisc_reinit() doesn't race with neither tty_ldisc_hangup()
nor set_ldisc() nor tty_ldisc_release() as they use tty lock.
But it races with anyone who expects line discipline to be the same
after hoding read semaphore in tty_ldisc_ref().
We've seen the following crash on v4.9.108 stable:
BUG: unable to handle kernel paging request at 0000000000002260
IP: [..] n_tty_receive_buf_common+0x5f/0x86d
Workqueue: events_unbound flush_to_ldisc
Call Trace:
[..] n_tty_receive_buf2
[..] tty_ldisc_receive_buf
[..] flush_to_ldisc
[..] process_one_work
[..] worker_thread
[..] kthread
[..] ret_from_fork
tty_ldisc_reinit() should be called with ldisc_sem hold for writing,
which will protect any reader against line discipline changes.
Cc: Jiri Slaby <[email protected]>
Cc: [email protected] # b027e2298bd5 ("tty: fix data race between tty_init_dev and flush of buf")
Reviewed-by: Jiri Slaby <[email protected]>
Reported-by: [email protected]
Tested-by: Mark Rutland <[email protected]>
Tested-by: Tetsuo Handa <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
Tested-by: Tycho Andersen <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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ldsem_down_read() will sleep if there is pending writer in the queue.
If the writer times out, readers in the queue should be woken up,
otherwise they may miss a chance to acquire the semaphore until the last
active reader will do ldsem_up_read().
There was a couple of reports where there was one active reader and
other readers soft locked up:
Showing all locks held in the system:
2 locks held by khungtaskd/17:
#0: (rcu_read_lock){......}, at: watchdog+0x124/0x6d1
#1: (tasklist_lock){.+.+..}, at: debug_show_all_locks+0x72/0x2d3
2 locks held by askfirst/123:
#0: (&tty->ldisc_sem){.+.+.+}, at: ldsem_down_read+0x46/0x58
#1: (&ldata->atomic_read_lock){+.+...}, at: n_tty_read+0x115/0xbe4
Prevent readers wait for active readers to release ldisc semaphore.
Link: lkml.kernel.org/r/[email protected]
Link: lkml.kernel.org/r/20180907045041.GF1110@shao2-debian
Cc: Jiri Slaby <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: [email protected]
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Dmitry Safonov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
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