At Fri, 29 Apr 2011 19:41:53 +0200, Melchior FRANZ wrote:
- Takashi Iwai -- Friday 29 April 2011:
Melchior FRANZ wrote:
The bug was introduced with commit ba3820ade317ee36e496b9b40d2ec3987dd4aef0 [...] when using KMS my notebook's[2] screen remains dark, because the backlight isn't turned on.
Could you check whether the patch below changes the behavior? If this cures, it means that the backlight-combo mode doesn't work on your machine.
Yes, that works. (Test was with fafc9929c668f8bae6dd1f109f33a86d2cb3c460, which is current HEAD.)
Looking at bugzilla, the problem seems like the case lbpc=0. What about the patch below instead?
Takashi
--- diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index a06ff07..ba60218 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -207,7 +207,8 @@ u32 intel_panel_get_backlight(struct drm_device *dev)
val &= ~1; pci_read_config_byte(dev->pdev, PCI_LBPC, &lbpc); - val *= lbpc; + if (lbpc) + val *= lbpc; } }