Re: [PATCH v2] imx_serial: set wake bit when we receive a data byte

[Philippe Mathieu-Daudé]

On 15/6/23 11:30, Martin Kaiser wrote:
> The linux kernel added a flood check for rx data recently in commmit

"Linux", "commit"

Also maybe s/rx/RX/ s/uart/UART/.

> 496a4471b7c3 ("serial: imx: work-around for hardware RX flood"). This
> check uses the wake bit in the uart status register 2. The wake bit
> indicates that the receiver detected a start bit on the rx line. If the
> kernel sees a number of rx interrupts without the wake bit being set, it
> treats this as spurious data and resets the uart port. imx_serial does
> never set the wake bit and triggers the kernel's flood check.
>
> This patch adds support for the wake bit. wake is set when we receive a
> new character (it's not set for break events). It seems that wake is
> cleared by the kernel driver, the hardware does not have to clear it
> automatically after data was read.
>
> The wake bit can be configured as an interrupt source. Support this
> mechanism as well.
>
> Co-developed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Thanks ;)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

> Signed-off-by: Martin Kaiser <martin@kaiser.cx>
> ---
> v2:
>   - support interrupts from wake
>   - clean up the commit message
>
>   hw/char/imx_serial.c         | 5 ++++-
>   include/hw/char/imx_serial.h | 1 +
>   2 files changed, 5 insertions(+), 1 deletion(-)