[Intel-gfx] [PATCH 2/2] drm/i915: Check some transcoder timing minimum limits

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

On ILK+ the documented min hdisplay is 64, min hblank is 32, and min
vblank is 5. On earlier platforms min hblank is also 32, and min
vblank is 3. Make sure the mode satisfies those limits.

There are further limits for HDMI and pfit use cases, but we'll check
for those in a more specific location.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_display.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index e25b82d07d4f..1141f4aa31c7 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -15816,6 +15816,21 @@ intel_mode_valid(struct drm_device *dev,
 	    mode->vtotal > vtotal_max)
 		return MODE_V_ILLEGAL;
 
+	if (INTEL_GEN(dev_priv) >= 5) {
+		if (mode->hdisplay < 64 ||
+		    mode->htotal - mode->hdisplay < 32)
+			return MODE_H_ILLEGAL;
+
+		if (mode->vtotal - mode->vdisplay < 5)
+			return MODE_V_ILLEGAL;
+	} else {
+		if (mode->htotal - mode->hdisplay < 32)
+			return MODE_H_ILLEGAL;
+
+		if (mode->vtotal - mode->vdisplay < 3)
+			return MODE_V_ILLEGAL;
+	}
+
 	return MODE_OK;
 }
 
-- 
2.21.0