drm/i915: workaround IGD i2c bus issue in kernel side (v2)
In IGD, DPCUNIT_CLOCK_GATE_DISABLE bit should be set, otherwise i2c
access will be wrong.
v2: Disable CLOCK_GATE_DISABLE bit after bit bashing as suggested by Eric.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_modes.c b/drivers/gpu/drm/i915/intel_modes.c
index 07d7ec9..e0910fe 100644
--- a/drivers/gpu/drm/i915/intel_modes.c
+++ b/drivers/gpu/drm/i915/intel_modes.c
@@ -27,6 +27,7 @@
#include <linux/fb.h>
#include "drmP.h"
#include "intel_drv.h"
+#include "i915_drv.h"
/**
* intel_ddc_probe
@@ -52,7 +53,10 @@
}
};
+ intel_i2c_quirk_set(intel_output->ddc_bus->drm_dev, true);
ret = i2c_transfer(&intel_output->ddc_bus->adapter, msgs, 2);
+ intel_i2c_quirk_set(intel_output->ddc_bus->drm_dev, false);
+
if (ret == 2)
return true;
@@ -70,8 +74,10 @@
struct edid *edid;
int ret = 0;
+ intel_i2c_quirk_set(intel_output->ddc_bus->drm_dev, true);
edid = drm_get_edid(&intel_output->base,
&intel_output->ddc_bus->adapter);
+ intel_i2c_quirk_set(intel_output->ddc_bus->drm_dev, false);
if (edid) {
drm_mode_connector_update_edid_property(&intel_output->base,
edid);