Commit 6292b8ef authored by Ville Syrjälä's avatar Ville Syrjälä

drm/edid: Fix off-by-one in DispID DTD pixel clock

The DispID DTD pixel clock is documented as:
"00 00 00 h → FF FF FF h | Pixel clock ÷ 10,000 0.01 → 167,772.16 Mega Pixels per Sec"
Which seems to imply that we to add one to the raw value.

Reality seems to agree as there are tiled displays in the wild
which currently show a 10kHz difference in the pixel clock
between the tiles (one tile gets its mode from the base EDID,
the other from the DispID block).

Cc: stable@vger.kernel.org
References: https://gitlab.freedesktop.org/drm/intel/-/issues/27Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200423151743.18767-1-ville.syrjala@linux.intel.comReviewed-by: default avatarManasi Navare <manasi.d.navare@intel.com>
parent 9da67433
...@@ -5111,7 +5111,7 @@ static struct drm_display_mode *drm_mode_displayid_detailed(struct drm_device *d ...@@ -5111,7 +5111,7 @@ static struct drm_display_mode *drm_mode_displayid_detailed(struct drm_device *d
struct drm_display_mode *mode; struct drm_display_mode *mode;
unsigned pixel_clock = (timings->pixel_clock[0] | unsigned pixel_clock = (timings->pixel_clock[0] |
(timings->pixel_clock[1] << 8) | (timings->pixel_clock[1] << 8) |
(timings->pixel_clock[2] << 16)); (timings->pixel_clock[2] << 16)) + 1;
unsigned hactive = (timings->hactive[0] | timings->hactive[1] << 8) + 1; unsigned hactive = (timings->hactive[0] | timings->hactive[1] << 8) + 1;
unsigned hblank = (timings->hblank[0] | timings->hblank[1] << 8) + 1; unsigned hblank = (timings->hblank[0] | timings->hblank[1] << 8) + 1;
unsigned hsync = (timings->hsync[0] | (timings->hsync[1] & 0x7f) << 8) + 1; unsigned hsync = (timings->hsync[0] | (timings->hsync[1] & 0x7f) << 8) + 1;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment