From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Lu Subject: Re: [Intel-gfx] Linux 3.11-rc2 [backlight] [ASUS N56VZ] Date: Tue, 30 Jul 2013 07:38:05 +0800 Message-ID: <51F6FCDD.3010300@intel.com> References: <2024506.rXjN91yI0W@vostro.rjw.lan> <877ggeyg1p.fsf@intel.com> <5730704.o2aLKRMvVz@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mga02.intel.com ([134.134.136.20]:23457 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750946Ab3G2Xhh (ORCPT ); Mon, 29 Jul 2013 19:37:37 -0400 In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: =?UTF-8?B?KiBTQU3DjSAq?= Cc: "Rafael J. Wysocki" , Jani Nikula , Linus Torvalds , Matthew Garrett , intel-gfx , LKML , ACPI Devel Maling List , Igor Gnatenko On 07/30/2013 03:36 AM, * SAM=C3=8D * wrote: > Hi Rafael, >=20 >=20 > did you commit a full revert? > Because I am experiencing quite weird things in rc3. > Do we have a bug opened to discuss about it? Yes we have: https://bugzilla.kernel.org/show_bug.cgi?id=3D52951 I'll look into this issue. Thanks, Aaron >=20 > Here is what I can observe: > 1) During boot, probably when loading the driver, backlight gets off = (or=20 > to a level low enough to make me feel it is off) > 2) When I am playing with my Fn+x keys, I am getting a completely ful= l /=20 > completely low brightness with no intermediate steps > 3) When I am playing with my Fn+x keys while gnome brightness setting= s=20 > panel is open, I am recovering intermediate steps but the Fn+x keys=20 > behavior is inverted (the key supposed to lower the brightness make i= t=20 > increase and vice-versa. Note that the gnome brightness indicator als= o=20 > gets inverted). > 4) Playing with the mouse on gnome brightness settings is working,=20 > except that on the minimum level, backlight gets off > 5) Writing to /sys/class/backlight/intel_backlight/brightness works >=20 >=20 > Regards >=20 > On 07/25/2013 02:57 PM, Rafael J. Wysocki wrote: >> On Thursday, July 25, 2013 03:34:10 PM Jani Nikula wrote: >>> On Thu, 25 Jul 2013, "Rafael J. Wysocki" wrote: >>>> On Thursday, July 25, 2013 11:09:27 AM Jani Nikula wrote: >>>>> On Thu, 25 Jul 2013, "Rafael J. Wysocki" wrote: >>>>>> Well, I wonder what about the appended (untested) patch? >>>>> Rafael, before going there, I've been trying to wrap my (poor, ru= sty >>>>> after vacation) head around >>>>> >>>>> commit 8c5bd7adb2ce47e6aa39d17b2375f69b0c0aa255 >>>>> Author: Rafael J. Wysocki >>>>> Date: Thu Jul 18 02:08:06 2013 +0200 >>>>> >>>>> ACPI / video / i915: No ACPI backlight if firmware expects W= indows 8 >>>>> >>>>> and I can't see how it could work. >>>> Well, if it didn't work, people wouldn't see either improvement or= breakage >>>> from it, but they do see that, so it evidently works. :-) >>> I didn't claim it didn't work, just that *I* didn't see how it coul= d. ;) >>> >>>>> First, the ACPI_VIDEO_SKIP_BACKLIGHT flag seems to be checked bef= ore >>>>> it's actually set anywhere. >>>> Are you sure about that? >>>> >>>> acpi_video_bus_add() is the .add() callback routine for acpi_video= _bus which >>>> in fact is an ACPI driver (the naming sucks, but I didn't invent i= t). This >>>> means that acpi_video_bus_add() can only be called *after* acpi_vi= deo_bus >>>> has been registered with the ACPI subsystem (and the driver core).= That >>>> is done by acpi_bus_register_driver() and, guess what?, this happe= ns in >>>> __acpi_video_register(). So clearly, acpi_video_bus_add() *cannot= * run before >>>> __acpi_video_register(). >>> Right. I totally missed the call within the ternary operator. Thank= s for >>> the explanation, and apologies for the noise. >>> >>>>> Second, with i915 that has opregion support, __acpi_video_registe= r() >>>>> should only ever get called once. Which means the acpi_walk_names= pace() >>>>> with video_unregister_backlight() should never get called in regi= ster. >>>>> >>>>> Please enlighten me. >>>> Actually, that's correct, so we don't need the whole >>>> video_unregister_backlight() thing, calling acpi_video_backlight_q= uirks() would >>>> be sufficient. >>>> >>>> Ah, one more reason to do a full revert. I'm thinking, though, th= at I'll leave >>>> acpi_video_backlight_quirks() as is so that it can be used by >>>> acpi_video_bus_(start)|(stop)_devices(), because that doesn't seem= to cause >>>> problems to happen. >>> I observe that for the regular non-quirk acpi_video_register() call= , >>> acpi_video_backlight_quirks() won't be called during register, but = it >>> will get called later. This might have subtle effects later on, don= 't >>> you think? >> Yes, it might, but after dropping ACPI_VIDEO_SKIP_BACKLIGHT it shoul= d be OK. >> >>> As to the original problem, and your patch in this thread, what do = you >>> think about having another value in acpi_backlight kernel parameter= for >>> it? Having an i915 module parameter to tell acpi to use or not use >>> quirks seems odd, since the i915 is not really taking over >>> anything. It's just passing the info on to acpi. >> I agree, I'm going to send a full revert in a while and we'll think = what to >> do about all that later. >> >> Thanks, >> Rafael >> >> >=20 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html