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>
This commit is contained in:
Bryan Freed
2010-10-14 09:14:51 +01:00
committed by Chris Wilson
parent e60a0b107b
commit 6d139a87b7
3 changed files with 25 additions and 4 deletions

View File

@@ -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);
}
}