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

[José Roberto de Souza]

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.

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) {
-- 
2.19.1