Re: [Intel-gfx] [RFC PATCH 0/2] i915 brightness control
On Mon, 2010-09-13 at 18:48 +0100, Matthew Garrett wrote: I've looked into this issue more closely and think I've worked out the underlying problem. The system in question appears to have two GPUs and exposes two ACPI backlight devices. Both of these are associated with existing PCI devices, so we don't ignore either of them because of that. Further, one of them (the AMD one) implements the spec properly and should work. We don't seem to perform a more fine-grained check to identify whether every ACPI backlight has all the required methods, and so as a result we provide both the working one and the non-working one. Having thought about this some more, I don't think this is the right approach. We should be ensuring that every backlight ahs all the required methods and then dropping the one that doesn't. This should be replaced with a native i915 backlight, and I sent patches to do that last week. I agree. Your proposed design is good, and I have successfully tested your proposed patches[1] (after minor porting changes to Ubuntu Maverick's 2.6.35). Thanks very much Matthew! FYI, I have published an experimental Ubuntu Maverick PPA kernel[2] which includes your patches, plus my dell_laptop tweaks to inhibit the broken dell_backlight by a module param or dmi blacklist table (in lieu of a yet to be implemented more fine-grained check). -Kamal Mostafa ka...@canonical.com [1] 2010-09-08 [Intel-gfx] [PATCH] i915: Add native backlight control 2010-09-08 [Intel-gfx] [PATCH] Backlight: Add backlight type [2] https://launchpad.net/~kamalmostafa/+archive/linux-kamal-mjgbacklight signature.asc Description: This is a digitally signed message part ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] [RFC PATCH 0/2] i915 brightness control
On Wed, Jun 02, 2010 at 03:11:40PM -0700, Kamal Mostafa wrote: In order to avoid the often-dysfunctional native acpi brightness control methods, a new acpi_brightness_hook interface is made available. The i915 driver uses the new hook to take over brightness control. Boot with i915.brightness=0 to disable. I've looked into this issue more closely and think I've worked out the underlying problem. The system in question appears to have two GPUs and exposes two ACPI backlight devices. Both of these are associated with existing PCI devices, so we don't ignore either of them because of that. Further, one of them (the AMD one) implements the spec properly and should work. We don't seem to perform a more fine-grained check to identify whether every ACPI backlight has all the required methods, and so as a result we provide both the working one and the non-working one. Having thought about this some more, I don't think this is the right approach. We should be ensuring that every backlight ahs all the required methods and then dropping the one that doesn't. This should be replaced with a native i915 backlight, and I sent patches to do that last week. -- Matthew Garrett | mj...@srcf.ucam.org ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] [RFC PATCH 0/2] i915 brightness control
On Thu, Jun 03, 2010 at 12:20:39AM +0100, Pedro Ribeiro wrote: Are you sure this is a good idea to enable it by default just because of a problem with one manufacturer (Dell)? It should (a-ha ha) be entirely safe on systems using the IGD opregion spec. My Lenovo laptop has fine brightness control with a GM45 and this may break it. Might be safer only to enable it for laptops with known problems. You have a complete list of all laptops with problems in this area? The ongoing situation with Windows 7 compatibility breaking machines that previously worked suggests that there's something going on which we don't understand or implement. -- Matthew Garrett | mj...@srcf.ucam.org ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
Re: [Intel-gfx] [RFC PATCH 0/2] i915 brightness control
On 2 June 2010 23:11, Kamal Mostafa ka...@canonical.com wrote: Requesting comments on this idea (proposed by Matthew Garrett) and my implementation. Note especially the KNOWN PROBLEM with a GM45 GPU. -Kamal ... BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/568611 In order to avoid the often-dysfunctional native acpi brightness control methods, a new acpi_brightness_hook interface is made available. The i915 driver uses the new hook to take over brightness control. Boot with i915.brightness=0 to disable. KNOWN PROBLEM: - i915 opregion brightness control silently fails on GM45 (pci-id 0x2a42) [RFC PATCH 1/2] acpi/video: acpi_brightness_hook API [RFC PATCH 2/2] drm/i915: override acpi brightness control ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx Are you sure this is a good idea to enable it by default just because of a problem with one manufacturer (Dell)? My Lenovo laptop has fine brightness control with a GM45 and this may break it. Might be safer only to enable it for laptops with known problems. Regards, Pedro ___ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/intel-gfx
