[Intel-gfx] [PATCH v3 09/10] drm/i915: Keep PSR disabled after a driver reload after a PSR error

[Dhinakaran Pandiyan]

On Thu, 2018-10-25 at 18:17 -0700, José Roberto de Souza wrote:
> If a PSR error happened and the driver is reloaded, the EDP_PSR_IIR
> will still keep the error set even after the reset done in the
> irq_preinstall and irq_uninstall hooks.

Does this happen or are you suspecting it might? Is this because IIR
clearing did not work or is it because of a new unhandled interrupt?

-DK



> And enabling in this situation cause the screen to freeze in the
> first time that PSR HW tries to activate so lets keep PSR disabled
> to avoid any rendering problems.
> 
> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_psr.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_psr.c
> b/drivers/gpu/drm/i915/intel_psr.c
> index 68201cc24d25..718270da1061 100644
> --- a/drivers/gpu/drm/i915/intel_psr.c
> +++ b/drivers/gpu/drm/i915/intel_psr.c
> @@ -529,6 +529,19 @@ void intel_psr_compute_config(struct intel_dp
> *intel_dp,
>  		return;
>  	}
>  
> +	/*
> +	 * If a PSR error happened and the driver is reloaded, the
> EDP_PSR_IIR
> +	 * will still keep the error set even after the reset done in
> the
> +	 * irq_preinstall and irq_uninstall hooks.
> +	 * And enabling in this situation cause the screen to freeze in
> the
> +	 * first time that PSR HW tries to activate so lets keep PSR
> disabled
> +	 * to avoid any rendering problems.
> +	 */
> +	if (I915_READ(EDP_PSR_IIR) & EDP_PSR_ERROR(TRANSCODER_EDP)) {
> +		DRM_DEBUG_KMS("PSR interruption error set\n");
> +		return;
> +	}
> +
>  	if (IS_HASWELL(dev_priv) &&
>  	    I915_READ(HSW_STEREO_3D_CTL(crtc_state->cpu_transcoder)) &
>  		      S3D_ENABLE) {