Re: [PATCH 6.6.y] drm/amd/display: Validate function returns

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] drm/amd/display: early return in dc_dmub_srv_cmd_run_list() drops diagnostics
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commit a641a7a2bd113ef9410e77f8cb3dd3d38d42ca71
Author: Alex Hung <alex.hung@amd.com>

drm/amd/display: Validate function returns

This commit adds checks for function return values to fix Coverity issues.
It handles errors from dmub_srv_wait_for_idle, dc_get_edp_link_panel_inst,
hubbub1_program_pstate_watermarks, and link_detect_connection_type.

> diff --git a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
> index 30a79dffbd37a..b3f02f451535a 100644
> --- a/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
> +++ b/drivers/gpu/drm/amd/display/dc/dc_dmub_srv.c
> @@ -144,7 +144,9 @@ bool dc_dmub_srv_cmd_run_list(struct dc_dmub_srv *dc_dmub_srv, unsigned int coun
>  		if (status == DMUB_STATUS_QUEUE_FULL) {
>  			/* Execute and wait for queue to become empty again. */
>  			dmub_srv_cmd_execute(dmub);
> -			dmub_srv_wait_for_idle(dmub, 100000);
> +			status = dmub_srv_wait_for_idle(dmub, 100000);
> +			if (status != DMUB_STATUS_OK)
> +				return false;
>  
>  			/* Requeue the command. */
>  			status = dmub_srv_cmd_queue(dmub, &cmd_list[i]);
>  		}

[Severity: Medium]
Does this new early return inadvertently bypass the diagnostic data collection?

Looking at dc_dmub_srv_cmd_run_list(), right after this block there is an
error handler for when the queue or wait fails:

		if (status != DMUB_STATUS_OK) {
			DC_ERROR("Error queueing DMUB command: status=%d\n", status);
			dc_dmub_srv_log_diagnostic_data(dc_dmub_srv);
			return false;
		}

By returning false directly when dmub_srv_wait_for_idle() fails, we skip
dc_dmub_srv_log_diagnostic_data() and the DC_ERROR logging. Could we
instead let it fall through or break here so that the existing error
handler can collect this diagnostic data?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260929031602.87583-1-artem@trailofbits.com?part=1