[PATCH 1/1] amdgpu/pm: Clarify Documentation of error handling in send_smc_mesg

[Paul Menzel]

Dear Darren,


Thank you for your patch.

Am 08.04.22 um 04:26 schrieb Darren Powell:
>   Contrary to the smu_cmn_send_smc_msg_with_param documentation, two
>   cases exist where messages are silently dropped with no error returned
>   to the caller. These cases occur in unusual situations where either:
>    1. the caller is a virtual GPU, or
>    2. a PCI recovery is underway and the HW is not yet in sync with the SW
> 
>   For more details see
>    commit 4ea5081c82c4 ("drm/amd/powerplay: enable SMC message filter")
>    commit bf36b52e781d ("drm/amdgpu: Avoid accessing HW when suspending SW state")

Please remove the indentation. If you re-rolled the patch, you could 
also spell *documentation* lowercase in the commit message summary.

> Signed-off-by: Darren Powell <darren.powell at amd.com>
> ---
>   drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c | 7 +++++--
>   1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> index b8d0c70ff668..b1bd1990c88b 100644
> --- a/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> +++ b/drivers/gpu/drm/amd/pm/swsmu/smu_cmn.c
> @@ -356,12 +356,15 @@ int smu_cmn_wait_for_response(struct smu_context *smu)
>    * completion of the command, and return back a value from the SMU in
>    * @read_arg pointer.
>    *
> - * Return 0 on success, -errno on error, if we weren't able to send
> + * Return 0 on success, or if the message is dropped.
> + * On error, -errno is returned if we weren't able to send
>    * the message or if the message completed with some kind of
>    * error. See __smu_cmn_reg2errno() for details of the -errno.
>    *
>    * If we weren't able to send the message to the SMU, we also print
> - * the error to the standard log.
> + * the error to the standard log. Dropped messages can be caused
> + * due to PCI slot recovery or attempting to send from a virtual GPU,
> + * and do not print an error.
>    *
>    * Command completion status is printed only if the -errno is
>    * -EREMOTEIO, indicating that the SMU returned back an
> 
> base-commit: 4585c45a6a66cb17cc97f4370457503746e540b7

The diff looks good – despite Mozilla Thunderbird quoting it strangely.


Kind regards,

Paul