drm/i915/bxt: IPC WA for Broxton
Display Workarounds #1135
If IPC is enabled in BXT, display underruns are observed.
WA: The Line Time programmed in the WM_LINETIME register should be
half of the actual calculated Line Time.
Programmed Line Time = 1/2*Calculated Line Time
Changes since V1:
- Add Workaround number in commit & code
Changes since V2 (from Paulo):
- Bikeshed white space and make the WA tag look like the others
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161201154940.24446-3-mahesh1.kumar@intel.com
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 5fe27e4..d2cc28f 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1239,6 +1239,8 @@ int i915_driver_load(struct pci_dev *pdev, const struct pci_device_id *ent)
intel_runtime_pm_enable(dev_priv);
+ dev_priv->ipc_enabled = false;
+
/* Everything is in place, we can now relax! */
DRM_INFO("Initialized %s %d.%d.%d %s for %s on minor %d\n",
driver.name, driver.major, driver.minor, driver.patchlevel,