drm/i915: Initialize panel timing registers if VBIOS did not
The time between start of the pixel clock and backlight enable is a basic
panel timing constraint. If the Panel Power On/Off registers are found
to be 0, assume we are booting without VBIOS initialization and set these
registers to something reasonable.
Change-Id: Ibed6cc10d46bf52fd92e0beb25ae3525b5eef99d
Signed-off-by: Bryan Freed <bfreed@chromium.org>
[ickle: rearranged into a separate function to distinguish its role from
simply parsing the VBIOS tables.]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index 2caf43d..35d121c 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1235,7 +1235,7 @@
*/
dev_priv->allow_batchbuffer = 1;
- ret = intel_init_bios(dev);
+ ret = intel_parse_bios(dev);
if (ret)
DRM_INFO("failed to find VBIOS tables\n");
@@ -2001,6 +2001,9 @@
intel_setup_gmbus(dev);
intel_opregion_setup(dev);
+ /* Make sure the bios did its job and set up vital registers */
+ intel_setup_bios(dev);
+
i915_gem_load(dev);
/* Init HWS */
diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index cc15447..b9560f3 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -577,7 +577,7 @@
}
/**
- * intel_init_bios - initialize VBIOS settings & find VBT
+ * intel_parse_bios - find VBT and initialize settings from the BIOS
* @dev: DRM device
*
* Loads the Video BIOS and checks that the VBT exists. Sets scratch registers
@@ -586,7 +586,7 @@
* Returns 0 on success, nonzero on failure.
*/
bool
-intel_init_bios(struct drm_device *dev)
+intel_parse_bios(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
struct pci_dev *pdev = dev->pdev;
@@ -647,3 +647,20 @@
return 0;
}
+
+/* Ensure that vital registers have been initialised, even if the BIOS
+ * is absent or just failing to do its job.
+ */
+void intel_setup_bios(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+
+ /* Set the Panel Power On/Off timings if uninitialized. */
+ if ((I915_READ(PP_ON_DELAYS) == 0) && (I915_READ(PP_OFF_DELAYS) == 0)) {
+ /* Set T2 to 40ms and T5 to 200ms */
+ I915_WRITE(PP_ON_DELAYS, 0x019007d0);
+
+ /* Set T3 to 35ms and Tx to 200ms */
+ I915_WRITE(PP_OFF_DELAYS, 0x015e07d0);
+ }
+}
diff --git a/drivers/gpu/drm/i915/intel_bios.h b/drivers/gpu/drm/i915/intel_bios.h
index e1a598f..5f8e4ed 100644
--- a/drivers/gpu/drm/i915/intel_bios.h
+++ b/drivers/gpu/drm/i915/intel_bios.h
@@ -467,7 +467,8 @@
struct edp_link_params link_params[16];
} __attribute__ ((packed));
-bool intel_init_bios(struct drm_device *dev);
+void intel_setup_bios(struct drm_device *dev);
+bool intel_parse_bios(struct drm_device *dev);
/*
* Driver<->VBIOS interaction occurs through scratch bits in