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 2caf43de8a6a403d3364d35a93fdf803fa00d75d..35d121c70a1fbd4e5f39b5098e4139340ff435b6 100644 (file)
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1235,7 +1235,7 @@ static int i915_load_modeset_init(struct drm_device *dev,
         */
        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 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
        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 cc15447eff410ad8712357e69b2dc85f1f8acafb..b9560f3cbb3da6e22e79a32ec6e987e71b6ba070 100644 (file)
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -577,7 +577,7 @@ init_vbt_defaults(struct drm_i915_private *dev_priv)
 }
 
 /**
- * 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 @@ init_vbt_defaults(struct drm_i915_private *dev_priv)
  * 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 @@ intel_init_bios(struct drm_device *dev)
 
        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 e1a598f2a96684e6e895748a18b91b28f6253b4a..5f8e4edcbbb901937a20a522f60057ea762a0a9d 100644 (file)
--- a/drivers/gpu/drm/i915/intel_bios.h
+++ b/drivers/gpu/drm/i915/intel_bios.h
@@ -467,7 +467,8 @@ struct bdb_edp {
        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