drm/i915: Check PSR setup time vs. vblank length
Bspec says:
"Restriction : SRD must not be enabled when the PSR Setup time from DPCD
00071h is greater than the time for vertical blank minus one line."
Let's check for that and disallow PSR if we exceed the limit.
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 0de935a..7c08e4f 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -53,8 +53,8 @@
}
}
-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 @@
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();