Re: [PATCH] drm/i915/display: Do not report timeout on suspend

[Jani Nikula <jani.nikula@linux.intel.com>]

On Fri, 13 Dec 2024, Jonathan Cavitt <jonathan.cavitt@intel.com> wrote:
> In intel_dp_aux_wait_done, we call intel_de_wait_custom.  This call has
> a 10ms timeout before reporting ETIMEDOUT.  However, if the display pm
> runtime is suspended, then it would be expected for this call to time
> out.  This may be the case, for example, during an engine reset.
>
> Do not report ETIMEDOUT here when the pm runtime is suspended.

No.

Please root cause how you hit this. This should not be possible.

intel_dp_aux_xfer() -> intel_display_power_get() -> intel_runtime_pm_get()

We hold this over the duration of aux communications. The patch at hand
is brushing something more serious under the carpet.

BR,
Jani.


>
> Signed-off-by: Jonathan Cavitt <jonathan.cavitt@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_dp_aux.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux.c b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> index 04a7acd7f73c..25c37398f930 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux.c
> @@ -66,7 +66,7 @@ intel_dp_aux_wait_done(struct intel_dp *intel_dp)
>  				   0,
>  				   2, timeout_ms, &status);
>  
> -	if (ret == -ETIMEDOUT)
> +	if (ret == -ETIMEDOUT && !pm_runtime_suspended(display->drm->dev))
>  		drm_err(display->drm,
>  			"%s: did not complete or timeout within %ums (status 0x%08x)\n",
>  			intel_dp->aux.name, timeout_ms, status);

-- 
Jani Nikula, Intel