As per BSPEC, valid cdclk values for glk are 79.2, 158.4, 316.8 Mhz.
Practically we can achive only 99% of these cdclk values. So cdclk
should be calculated for the given pixclk as per that otherwise it may
lead to screen corruption for some scenarios.

Signed-off-by: Madhav Chauhan <madhav.chau...@intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c 
b/drivers/gpu/drm/i915/intel_display.c
index 45e5874..2e1bfe9 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6544,9 +6544,9 @@ static int valleyview_calc_cdclk(struct drm_i915_private 
*dev_priv,
 
 static int glk_calc_cdclk(int max_pixclk)
 {
-       if (max_pixclk > 2 * 158400)
+       if (max_pixclk > DIV_ROUND_UP(2 * 158400 * 99, 100))
                return 316800;
-       else if (max_pixclk > 2 * 79200)
+       else if (max_pixclk > DIV_ROUND_UP(2 * 79200 * 99, 100))
                return 158400;
        else
                return 79200;
-- 
1.9.1

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx

Reply via email to