diff options
author | Mario Kleiner <mario.kleiner.de@gmail.com> | 2016-07-06 12:05:45 +0200 |
---|---|---|
committer | Jiri Slaby <jslaby@suse.cz> | 2016-08-19 09:51:19 +0200 |
commit | a2c511f6eb31bbb8233d2048e22a725bccf30494 (patch) | |
tree | 82f54516321e68834cabbc19299af375f21f1965 | |
parent | 7c1fb8ca3e876d4f8897f8f66c03bb2d915dab91 (diff) |
drm/i915/dp: Revert "drm/i915/dp: fall back to 18 bpp when sink capability is unknown"
commit 196f954e250943df414efd3d632254c29be38e59 upstream.
This reverts commit 013dd9e03872
("drm/i915/dp: fall back to 18 bpp when sink capability is unknown")
This commit introduced a regression into stable kernels,
as it reduces output color depth to 6 bpc for any video
sink connected to a Displayport connector if that sink
doesn't report a specific color depth via EDID, or if
our EDID parser doesn't actually recognize the proper
bpc from EDID.
Affected are active DisplayPort->VGA converters and
active DisplayPort->DVI converters. Both should be
able to handle 8 bpc, but are degraded to 6 bpc with
this patch.
The reverted commit was meant to fix
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=105331
A followup patch implements a fix for that specific bug,
which is caused by a faulty EDID of the affected DP panel
by adding a new EDID quirk for that panel.
DP 18 bpp fallback handling and other improvements to
DP sink bpc detection will be handled for future
kernels in a separate series of patches.
Please backport to stable.
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
-rw-r--r-- | drivers/gpu/drm/i915/intel_display.c | 20 |
1 files changed, 5 insertions, 15 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 05f8b51cd42a..57d5abc420d1 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -8220,21 +8220,11 @@ connected_sink_compute_bpp(struct intel_connector * connector, pipe_config->pipe_bpp = connector->base.display_info.bpc*3; } - /* Clamp bpp to default limit on screens without EDID 1.4 */ - if (connector->base.display_info.bpc == 0) { - int type = connector->base.connector_type; - int clamp_bpp = 24; - - /* Fall back to 18 bpp when DP sink capability is unknown. */ - if (type == DRM_MODE_CONNECTOR_DisplayPort || - type == DRM_MODE_CONNECTOR_eDP) - clamp_bpp = 18; - - if (bpp > clamp_bpp) { - DRM_DEBUG_KMS("clamping display bpp (was %d) to default limit of %d\n", - bpp, clamp_bpp); - pipe_config->pipe_bpp = clamp_bpp; - } + /* Clamp bpp to 8 on screens without EDID 1.4 */ + if (connector->base.display_info.bpc == 0 && bpp > 24) { + DRM_DEBUG_KMS("clamping display bpp (was %d) to default limit of 24\n", + bpp); + pipe_config->pipe_bpp = 24; } } |