[PATCH 3.8 073/166] drm/edid: add quirk for BPC in Samsung NP700G7A-S01PL notebook

Kamal Mostafa
2014-01-15T21:51:27Z

From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <zajec5@gmail.com>

commit 49d45a31b71d7d9da74485922bdb63faf3dc9684 upstream.

This bug in EDID was exposed by:

commit eccea7920cfb009c2fa40e9ecdce8c36f61cab66
Author: Alex Deucher <alexander.deucher@amd.com>
Date: Mon Mar 26 15:12:54 2012 -0400

drm/radeon/kms: improve bpc handling (v2)

Which resulted in kind of regression in 3.5. This fixes
https://bugs.freedesktop.org/show_bug.cgi?id=70934

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/gpu/drm/drm_edid.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 60d6b35..559f49b 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -68,6 +68,8 @@
#define EDID_QUIRK_DETAILED_SYNC_PP (1 << 6)
/* Force reduced-blanking timings for detailed modes */
#define EDID_QUIRK_FORCE_REDUCED_BLANKING (1 << 7)
+/* Force 8bpc */
+#define EDID_QUIRK_FORCE_8BPC (1 << 8)

struct detailed_mode_closure {
struct drm_connector *connector;
@@ -128,6 +130,9 @@ static struct edid_quirk {

/* Medion MD 30217 PG */
{ "MED", 0x7b8, EDID_QUIRK_PREFER_LARGE_75 },
+
+ /* Panel in Samsung NP700G7A-S01PL notebook reports 6bpc */
+ { "SEC", 0xd033, EDID_QUIRK_FORCE_8BPC },
};

/*** DDC fetch and block validation ***/
@@ -2034,6 +2039,9 @@ int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid)

drm_add_display_info(edid, &connector->display_info);

+ if (quirks & EDID_QUIRK_FORCE_8BPC)
+ connector->display_info.bpc = 8;
+
return num_modes;
}
EXPORT_SYMBOL(drm_add_edid_modes);
--
1.8.3.2