[Bug 97918] [bdw regression 4.8] Severe graphics regression, rainbow glitching and flickering on Intel Broadwell 5500U integrated graphics

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=97918

--- Comment #3 from Nicholas Stommel <nicholas.stommel at gmail.com> ---
I propose a patch that can be applied from within the kernel source directory
for compilation that merely reverts those changes, let's call it
broadwell-gfx-fix.patch, which can be applied with 
patch -p1 < broadwell-gfx-patch
I am currently compiling the kernel with this patch in addition to the default
kernel patches at http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.7.5/
and hoping for the best!
The contents were generated by diff -u as follows:

--- linux-4.7.5/drivers/gpu/drm/i915/intel_opregion.c   2016-09-24
04:10:18.000000000 -0400
+++ linux-4.7.4/drivers/gpu/drm/i915/intel_opregion.c   2016-09-15
02:21:53.000000000 -0400
@@ -1013,23 +1013,6 @@
        return err;
 }

-static int intel_use_opregion_panel_type_callback(const struct dmi_system_id
*id)
-{
-       DRM_INFO("Using panel type from OpRegion on %s\n", id->ident);
-       return 1;
-}
-
-static const struct dmi_system_id intel_use_opregion_panel_type[] = {
-       {
-               .callback = intel_use_opregion_panel_type_callback,
-               .ident = "Conrac GmbH IX45GM2",
-               .matches = {DMI_MATCH(DMI_SYS_VENDOR, "Conrac GmbH"),
-                           DMI_MATCH(DMI_PRODUCT_NAME, "IX45GM2"),
-               },
-       },
-       { }
-};
-
 int
 intel_opregion_get_panel_type(struct drm_device *dev)
 {
@@ -1055,16 +1038,6 @@
                return -ENODEV;
        }

-       /*
-        * So far we know that some machined must use it, others must not use
it.
-        * There doesn't seem to be any way to determine which way to go,
except
-        * via a quirk list :(
-        */
-       if (!dmi_check_system(intel_use_opregion_panel_type)) {
-               DRM_DEBUG_KMS("Ignoring OpRegion panel type (%d)\n", ret - 1);
-               return -ENODEV;
-       }
-
        /*
         * FIXME On Dell XPS 13 9350 the OpRegion panel type (0) gives us
         * low vswing for eDP, whereas the VBT panel type (2) gives us normal

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