From 1f0d9cbeec9bb0a1c2013342836f2c9754d6502b Mon Sep 17 00:00:00 2001 From: Jae Hyun Yoo Date: Wed, 9 Oct 2019 14:20:34 -0700 Subject: i2c: aspeed: fix master pending state handling In case of master pending state, it should not trigger a master command, otherwise data could be corrupted because this H/W shares the same data buffer for slave and master operations. It also means that H/W command queue handling is unreliable because of the buffer sharing issue. To fix this issue, it clears command queue if a master command is queued in pending state to use S/W solution instead of H/W command queue handling. Also, it refines restarting mechanism of the pending master command. Fixes: 2e57b7cebb98 ("i2c: aspeed: Add multi-master use case support") Signed-off-by: Jae Hyun Yoo Reviewed-by: Brendan Higgins Acked-by: Joel Stanley Tested-by: Tao Ren Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-aspeed.c | 54 ++++++++++++++++++++++++++--------------- 1 file changed, 34 insertions(+), 20 deletions(-) (limited to 'drivers') diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c index fa66951b05d0..7b098ff5f5dd 100644 --- a/drivers/i2c/busses/i2c-aspeed.c +++ b/drivers/i2c/busses/i2c-aspeed.c @@ -108,6 +108,12 @@ #define ASPEED_I2CD_S_TX_CMD BIT(2) #define ASPEED_I2CD_M_TX_CMD BIT(1) #define ASPEED_I2CD_M_START_CMD BIT(0) +#define ASPEED_I2CD_MASTER_CMDS_MASK \ + (ASPEED_I2CD_M_STOP_CMD | \ + ASPEED_I2CD_M_S_RX_CMD_LAST | \ + ASPEED_I2CD_M_RX_CMD | \ + ASPEED_I2CD_M_TX_CMD | \ + ASPEED_I2CD_M_START_CMD) /* 0x18 : I2CD Slave Device Address Register */ #define ASPEED_I2CD_DEV_ADDR_MASK GENMASK(6, 0) @@ -336,18 +342,19 @@ static void aspeed_i2c_do_start(struct aspeed_i2c_bus *bus) struct i2c_msg *msg = &bus->msgs[bus->msgs_index]; u8 slave_addr = i2c_8bit_addr_from_msg(msg); - bus->master_state = ASPEED_I2C_MASTER_START; - #if IS_ENABLED(CONFIG_I2C_SLAVE) /* * If it's requested in the middle of a slave session, set the master * state to 'pending' then H/W will continue handling this master * command when the bus comes back to the idle state. */ - if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) + if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) { bus->master_state = ASPEED_I2C_MASTER_PENDING; + return; + } #endif /* CONFIG_I2C_SLAVE */ + bus->master_state = ASPEED_I2C_MASTER_START; bus->buf_index = 0; if (msg->flags & I2C_M_RD) { @@ -422,20 +429,6 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) } } -#if IS_ENABLED(CONFIG_I2C_SLAVE) - /* - * A pending master command will be started by H/W when the bus comes - * back to idle state after completing a slave operation so change the - * master state from 'pending' to 'start' at here if slave is inactive. - */ - if (bus->master_state == ASPEED_I2C_MASTER_PENDING) { - if (bus->slave_state != ASPEED_I2C_SLAVE_INACTIVE) - goto out_no_complete; - - bus->master_state = ASPEED_I2C_MASTER_START; - } -#endif /* CONFIG_I2C_SLAVE */ - /* Master is not currently active, irq was for someone else. */ if (bus->master_state == ASPEED_I2C_MASTER_INACTIVE || bus->master_state == ASPEED_I2C_MASTER_PENDING) @@ -462,11 +455,15 @@ static u32 aspeed_i2c_master_irq(struct aspeed_i2c_bus *bus, u32 irq_status) #if IS_ENABLED(CONFIG_I2C_SLAVE) /* * If a peer master starts a xfer immediately after it queues a - * master command, change its state to 'pending' then H/W will - * continue the queued master xfer just after completing the - * slave mode session. + * master command, clear the queued master command and change + * its state to 'pending'. To simplify handling of pending + * cases, it uses S/W solution instead of H/W command queue + * handling. */ if (unlikely(irq_status & ASPEED_I2CD_INTR_SLAVE_MATCH)) { + writel(readl(bus->base + ASPEED_I2C_CMD_REG) & + ~ASPEED_I2CD_MASTER_CMDS_MASK, + bus->base + ASPEED_I2C_CMD_REG); bus->master_state = ASPEED_I2C_MASTER_PENDING; dev_dbg(bus->dev, "master goes pending due to a slave start\n"); @@ -629,6 +626,14 @@ static irqreturn_t aspeed_i2c_bus_irq(int irq, void *dev_id) irq_handled |= aspeed_i2c_master_irq(bus, irq_remaining); } + + /* + * Start a pending master command at here if a slave operation is + * completed. + */ + if (bus->master_state == ASPEED_I2C_MASTER_PENDING && + bus->slave_state == ASPEED_I2C_SLAVE_INACTIVE) + aspeed_i2c_do_start(bus); #else irq_handled = aspeed_i2c_master_irq(bus, irq_remaining); #endif /* CONFIG_I2C_SLAVE */ @@ -691,6 +696,15 @@ static int aspeed_i2c_master_xfer(struct i2c_adapter *adap, ASPEED_I2CD_BUS_BUSY_STS)) aspeed_i2c_recover_bus(bus); + /* + * If timed out and the state is still pending, drop the pending + * master command. + */ + spin_lock_irqsave(&bus->lock, flags); + if (bus->master_state == ASPEED_I2C_MASTER_PENDING) + bus->master_state = ASPEED_I2C_MASTER_INACTIVE; + spin_unlock_irqrestore(&bus->lock, flags); + return -ETIMEDOUT; } -- cgit From 62931ac2f9015ea38d80494ec37658ab3df6a6d7 Mon Sep 17 00:00:00 2001 From: Fabien Parent Date: Fri, 18 Oct 2019 19:32:13 +0200 Subject: i2c: mt65xx: fix NULL ptr dereference Since commit abf4923e97c3 ("i2c: mediatek: disable zero-length transfers for mt8183"), there is a NULL pointer dereference for all the SoCs that don't have any quirk. mtk_i2c_functionality is not checking that the quirks pointer is not NULL before starting to use it. This commit add a call to i2c_check_quirks which will check whether the quirks pointer is set, and if so will check if the IP has the NO_ZERO_LEN quirk. Fixes: abf4923e97c3 ("i2c: mediatek: disable zero-length transfers for mt8183") Signed-off-by: Fabien Parent Reviewed-by: Cengiz Can Reviewed-by: Hsin-Yi Wang Tested-by: Ulrich Hecht Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-mt65xx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index 29eae1bf4f86..2152ec5f535c 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -875,7 +875,7 @@ static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id) static u32 mtk_i2c_functionality(struct i2c_adapter *adap) { - if (adap->quirks->flags & I2C_AQ_NO_ZERO_LEN) + if (i2c_check_quirks(adap, I2C_AQ_NO_ZERO_LEN)) return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); else -- cgit From 02e64276c6dbcc4c5f39844f33d18180832a58f3 Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier Date: Mon, 30 Sep 2019 17:28:01 +0200 Subject: i2c: stm32f7: fix first byte to send in slave mode The slave-interface documentation [1] states "the bus driver should transmit the first byte" upon I2C_SLAVE_READ_REQUESTED slave event: - 'val': backend returns first byte to be sent The driver currently ignores the 1st byte to send on this event. [1] https://www.kernel.org/doc/Documentation/i2c/slave-interface Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support") Signed-off-by: Fabrice Gasnier Reviewed-by: Pierre-Yves MORDRET Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-stm32f7.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers') diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index d36cf08461f7..c8ce6c8dd404 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -1192,6 +1192,8 @@ static void stm32f7_i2c_slave_start(struct stm32f7_i2c_dev *i2c_dev) STM32F7_I2C_CR1_TXIE; stm32f7_i2c_set_bits(base + STM32F7_I2C_CR1, mask); + /* Write 1st data byte */ + writel_relaxed(value, base + STM32F7_I2C_TXDR); } else { /* Notify i2c slave that new write transfer is starting */ i2c_slave_event(slave, I2C_SLAVE_WRITE_REQUESTED, &value); -- cgit From 6d6b0d0d5afc8c4c84b08261260ba11dfa5206f2 Mon Sep 17 00:00:00 2001 From: Fabrice Gasnier Date: Tue, 1 Oct 2019 10:51:09 +0200 Subject: i2c: stm32f7: fix a race in slave mode with arbitration loss irq When in slave mode, an arbitration loss (ARLO) may be detected before the slave had a chance to detect the stop condition (STOPF in ISR). This is seen when two master + slave adapters switch their roles. It provokes the i2c bus to be stuck, busy as SCL line is stretched. - the I2C_SLAVE_STOP event is never generated due to STOPF flag is set but don't generate an irq (race with ARLO irq, STOPIE is masked). STOPF flag remains set until next master xfer (e.g. when STOPIE irq get unmasked). In this case, completion is generated too early: immediately upon new transfer request (then it doesn't send all data). - Some data get stuck in TXDR register. As a consequence, the controller stretches the SCL line: the bus gets busy until a future master transfer triggers the bus busy / recovery mechanism (this can take time... and may never happen at all) So choice is to let the STOPF being detected by the slave isr handler, to properly handle this stop condition. E.g. don't mask IRQs in error handler, when the slave is running. Fixes: 60d609f30de2 ("i2c: i2c-stm32f7: Add slave support") Signed-off-by: Fabrice Gasnier Reviewed-by: Pierre-Yves MORDRET Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-stm32f7.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'drivers') diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index c8ce6c8dd404..073bf57a9821 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -1503,7 +1503,7 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) void __iomem *base = i2c_dev->base; struct device *dev = i2c_dev->dev; struct stm32_i2c_dma *dma = i2c_dev->dma; - u32 mask, status; + u32 status; status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR); @@ -1528,12 +1528,15 @@ static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data) f7_msg->result = -EINVAL; } - /* Disable interrupts */ - if (stm32f7_i2c_is_slave_registered(i2c_dev)) - mask = STM32F7_I2C_XFER_IRQ_MASK; - else - mask = STM32F7_I2C_ALL_IRQ_MASK; - stm32f7_i2c_disable_irq(i2c_dev, mask); + if (!i2c_dev->slave_running) { + u32 mask; + /* Disable interrupts */ + if (stm32f7_i2c_is_slave_registered(i2c_dev)) + mask = STM32F7_I2C_XFER_IRQ_MASK; + else + mask = STM32F7_I2C_ALL_IRQ_MASK; + stm32f7_i2c_disable_irq(i2c_dev, mask); + } /* Disable dma */ if (i2c_dev->use_dma) { -- cgit From 348e46fbb4cdb2aead79aee1fd8bb25ec5fd25db Mon Sep 17 00:00:00 2001 From: Alain Volmat Date: Tue, 15 Oct 2019 15:11:58 +0200 Subject: i2c: stm32f7: remove warning when compiling with W=1 Remove the following warning: drivers/i2c/busses/i2c-stm32f7.c:315: warning: cannot understand function prototype: 'struct stm32f7_i2c_spec i2c_specs[] = Replace a comment starting with /** by simply /* to avoid having it interpreted as a kernel-doc comment. Fixes: aeb068c57214 ("i2c: i2c-stm32f7: add driver") Signed-off-by: Alain Volmat Reviewed-by: Pierre-Yves MORDRET Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-stm32f7.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c index 073bf57a9821..b24e7b937f21 100644 --- a/drivers/i2c/busses/i2c-stm32f7.c +++ b/drivers/i2c/busses/i2c-stm32f7.c @@ -305,7 +305,7 @@ struct stm32f7_i2c_dev { struct regmap *regmap; }; -/** +/* * All these values are coming from I2C Specification, Version 6.0, 4th of * April 2014. * -- cgit