diff options
| author | George G. Davis <[email protected]> | 2019-05-14 23:29:34 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <[email protected]> | 2019-05-21 12:18:17 +0200 |
| commit | 099506cbbc79c0bd52b19cb6b930f256dabc3950 (patch) | |
| tree | 6f62ffb39a5a262fd15ec6541953bffea7ba991f | |
| parent | 8178eeb3e8007d29b1e9dfd3c4d0f90de0f6ce55 (diff) | |
serial: sh-sci: disable DMA for uart_console
As noted in commit 84b40e3b57ee ("serial: 8250: omap: Disable DMA for
console UART"), UART console lines use low-level PIO only access functions
which will conflict with use of the line when DMA is enabled, e.g. when
the console line is also used for systemd messages. So disable DMA
support for UART console lines.
Reported-by: Michael Rodin <[email protected]>
Link: https://patchwork.kernel.org/patch/10929511/
Tested-by: Eugeniu Rosca <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Reviewed-by: Wolfram Sang <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Cc: [email protected]
Signed-off-by: George G. Davis <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
| -rw-r--r-- | drivers/tty/serial/sh-sci.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 3cd139752d3f..abc705716aa0 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1557,6 +1557,13 @@ static void sci_request_dma(struct uart_port *port) dev_dbg(port->dev, "%s: port %d\n", __func__, port->line); + /* + * DMA on console may interfere with Kernel log messages which use + * plain putchar(). So, simply don't use it with a console. + */ + if (uart_console(port)) + return; + if (!port->dev->of_node) return; |