On 09/26/2014 03:58 AM, Rafael J. Wysocki wrote:
On Thursday, September 25, 2014 11:15:35 AM Aaron Lu wrote:
Hi Hans,
Thanks for following up and explaining the situation to Pali.
On 09/25/2014 02:21 AM, Pali Rohár wrote:
On Wednesday 24 September 2014 16:34:21 Hans de Goede wrote:
Ok, so the dell-laptop interface is just an obsolete wrapper around the i915 opregion code, which shows that the right interface to use is the i915 one, which we do if you don't specify any kernel commandline parameters, case closed.
Regards,
Hans
Nope, its not closed.
Still i915 interface has problem with setting backlight. It exports lot of levels which turning display off. Which breaking exiting applications for configuring display brightness. This is still big regression as black screen is not want people want to see.
Driver dell-laptop has exported only few - not thousands level (which is insane) and only usefull levels (not lot of levels which turn display off).
So for this reason using i915 backlight interface is not possible and also Dell (for E6440) set kernel param acpi_backlight=vendor to use dell_laptop module for controlling brightness.
On my laptop E6440 is better for using dell-laptop and not acpi or i915.
Hi Pali,
Please test this patch:
diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c index ca52ad2ae7d1..15534345bd57 100644 --- a/drivers/gpu/drm/i915/intel_opregion.c +++ b/drivers/gpu/drm/i915/intel_opregion.c @@ -396,6 +396,24 @@ int intel_opregion_notify_adapter(struct drm_device *dev, pci_power_t state) return -EINVAL; }
+/*
- Some of the Thinkpads' firmware will issue a backlight change operation
- region request unconditionally on AC plug/unplug, this is undesirable and
- should be ignored. Then there is a Dell laptop whose vendor backlight
- interface also makes use of operation region request to change backlight
- level and we have to keep it work. The rule used here is: if the vendor
- backlight interface is not in use and the ACPI backlight interface is
- broken, we ignore the requests; oterwise, we keep processing them.
- */
+static bool should_ignore_backlight_request(void) +{
- if (acpi_video_backlight_support() &&
!acpi_video_verify_backlight_support())return true;- return false;
+}
Well, what about
return acpi_video_backlight_support() && !acpi_video_verify_backlight_support();
?
Yes that's better. Will send out a patch with this change, thanks for the suggestion.
-Aaron
static u32 asle_set_backlight(struct drm_device *dev, u32 bclp) { struct drm_i915_private *dev_priv = dev->dev_private; @@ -404,11 +422,7 @@ static u32 asle_set_backlight(struct drm_device *dev, u32 bclp)
DRM_DEBUG_DRIVER("bclp = 0x%08x\n", bclp);
- /*
* If the acpi_video interface is not supposed to be used, don't* bother processing backlight level change requests from firmware.*/- if (!acpi_video_verify_backlight_support()) {
- if (should_ignore_backlight_request()) { DRM_DEBUG_KMS("opregion backlight request ignored\n"); return 0; }
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