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authorHans de Goede <hdegoede@redhat.com>2013-01-11 12:08:56 +0100
committerDave Airlie <airlied@redhat.com>2013-01-14 08:44:02 +1000
commitc930812fe5ebe725760422c9c351d1f6fde1502d (patch)
tree035009bfa7c2b43742b39489a2628f63d2ba143b /drivers/gpu/drm/udl
parent7d00813f68cea787cedc7251e46b3596a8cfba97 (diff)
udldrmfb: Fix EDID not working with monitors with EDID extension blocks
udldrmfb only reads the main EDID block, and if that advertises extensions the drm_edid code expects them to be present, and starts reading beyond the buffer udldrmfb passes it. Although it may be possible to read more EDID info with the udl we simpy don't know how, and even if trial and error gets it working on one device, that is no guarantee it will work on other revisions. So this patch does a simple fix in the form of patching the EDID info to report 0 extension blocks, this fixes udldrmfb only doing 1024x768 on monitors with EDID extension blocks. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/udl')
-rw-r--r--drivers/gpu/drm/udl/udl_connector.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/gpu/drm/udl/udl_connector.c b/drivers/gpu/drm/udl/udl_connector.c
index 512f44add89f..3e6208f773e2 100644
--- a/drivers/gpu/drm/udl/udl_connector.c
+++ b/drivers/gpu/drm/udl/udl_connector.c
@@ -57,6 +57,14 @@ static int udl_get_modes(struct drm_connector *connector)
edid = (struct edid *)udl_get_edid(udl);
+ /*
+ * We only read the main block, but if the monitor reports extension
+ * blocks then the drm edid code expects them to be present, so patch
+ * the extension count to 0.
+ */
+ edid->checksum += edid->extensions;
+ edid->extensions = 0;
+
drm_mode_connector_update_edid_property(connector, edid);
ret = drm_add_edid_modes(connector, edid);
kfree(edid);