Merge tag 'drm-psr-fixes-for-v4.8' of git://people.freedesktop.org/~airlied/linux

Pull i915 drm fixes from Dave Airlie:
 "These are the two fixes from Ville for the bug you are seeing on your
  HSW laptop.

  They pretty much disable PSR in some cases where the panel reports a
  setup time that would cause issues, like you seem to have"

* tag 'drm-psr-fixes-for-v4.8' of git://people.freedesktop.org/~airlied/linux:
  drm/i915: Check PSR setup time vs. vblank length
  drm/dp: Add drm_dp_psr_setup_time()

5 files changed, 57 insertions, 4 deletions

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 8f11b8741e42..eae5ef963cb7 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -860,3 +860,35 @@ void drm_dp_aux_unregister(struct drm_dp_aux *aux)
         i2c_del_adapter(&aux->ddc);
 }
 EXPORT_SYMBOL(drm_dp_aux_unregister);
+
+#define PSR_SETUP_TIME(x) [DP_PSR_SETUP_TIME_ ## x >> DP_PSR_SETUP_TIME_SHIFT] = (x)
+
+/**
+ * drm_dp_psr_setup_time() - PSR setup in time usec
+ * @psr_cap: PSR capabilities from DPCD
+ *
+ * Returns:
+ * PSR setup time for the panel in microseconds,  negative
+ * error code on failure.
+ */
+int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE])
+{
+        static const u16 psr_setup_time_us[] = {
+                PSR_SETUP_TIME(330),
+                PSR_SETUP_TIME(275),
+                PSR_SETUP_TIME(165),
+                PSR_SETUP_TIME(110),
+                PSR_SETUP_TIME(55),
+                PSR_SETUP_TIME(0),
+        };
+        int i;
+
+        i = (psr_cap[1] & DP_PSR_SETUP_TIME_MASK) >> DP_PSR_SETUP_TIME_SHIFT;
+        if (i >= ARRAY_SIZE(psr_setup_time_us))
+                return -EINVAL;
+
+        return psr_setup_time_us[i];
+}
+EXPORT_SYMBOL(drm_dp_psr_setup_time);
+
+#undef PSR_SETUP_TIME
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 3329fc6a95f4..cc937a19b1ba 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1730,6 +1730,8 @@ bool intel_sdvo_init(struct drm_device *dev,
 
 
 /* intel_sprite.c */
+int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode,
+                             int usecs);
 int intel_plane_init(struct drm_device *dev, enum pipe pipe, int plane);
 int intel_sprite_set_colorkey(struct drm_device *dev, void *data,
                               struct drm_file *file_priv);
diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index 68bd0bb34817..2b0d1baf15b3 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -327,6 +327,9 @@ static bool intel_psr_match_conditions(struct intel_dp *intel_dp)
         struct drm_i915_private *dev_priv = to_i915(dev);
         struct drm_crtc *crtc = dig_port->base.base.crtc;
         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+        const struct drm_display_mode *adjusted_mode =
+                &intel_crtc->config->base.adjusted_mode;
+        int psr_setup_time;
 
         lockdep_assert_held(&dev_priv->psr.lock);
         WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
@@ -365,11 +368,25 @@ static bool intel_psr_match_conditions(struct intel_dp *intel_dp)
         }
 
         if (IS_HASWELL(dev) &&
-            intel_crtc->config->base.adjusted_mode.flags & DRM_MODE_FLAG_INTERLACE) {
+            adjusted_mode->flags & DRM_MODE_FLAG_INTERLACE) {
                 DRM_DEBUG_KMS("PSR condition failed: Interlaced is Enabled\n");
                 return false;
         }
 
+        psr_setup_time = drm_dp_psr_setup_time(intel_dp->psr_dpcd);
+        if (psr_setup_time < 0) {
+                DRM_DEBUG_KMS("PSR condition failed: Invalid PSR setup time (0x%02x)\n",
+                              intel_dp->psr_dpcd[1]);
+                return false;
+        }
+
+        if (intel_usecs_to_scanlines(adjusted_mode, psr_setup_time) >
+            adjusted_mode->crtc_vtotal - adjusted_mode->crtc_vdisplay - 1) {
+                DRM_DEBUG_KMS("PSR condition failed: PSR setup time (%d us) too long\n",
+                              psr_setup_time);
+                return false;
+        }
+
         dev_priv->psr.source_ok = true;
         return true;
 }
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 0de935ad01c2..7c08e4f29032 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -53,8 +53,8 @@ format_is_yuv(uint32_t format)
         }
 }
 
-static int usecs_to_scanlines(const struct drm_display_mode *adjusted_mode,
-                              int usecs)
+int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode,
+                             int usecs)
 {
         /* paranoia */
         if (!adjusted_mode->crtc_htotal)
@@ -91,7 +91,7 @@ void intel_pipe_update_start(struct intel_crtc *crtc)
                 vblank_start = DIV_ROUND_UP(vblank_start, 2);
 
         /* FIXME needs to be calibrated sensibly */
-        min = vblank_start - usecs_to_scanlines(adjusted_mode, 100);
+        min = vblank_start - intel_usecs_to_scanlines(adjusted_mode, 100);
         max = vblank_start - 1;
 
         local_irq_disable();
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 72dee1213268..63b8bd502444 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -657,6 +657,8 @@ struct edp_vsc_psr {
 #define EDP_VSC_PSR_UPDATE_RFB          (1<<1)
 #define EDP_VSC_PSR_CRC_VALUES_VALID    (1<<2)
 
+int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]);
+
 static inline int
 drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 {