From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752949AbdCFEwE (ORCPT ); Sun, 5 Mar 2017 23:52:04 -0500 Received: from mail-lf0-f65.google.com ([209.85.215.65]:33974 "EHLO mail-lf0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752866AbdCFEuh (ORCPT ); Sun, 5 Mar 2017 23:50:37 -0500 Date: Mon, 6 Mar 2017 05:49:05 +0100 From: =?utf-8?B?TWljaGHFgiBLxJlwaWXFhA==?= To: Jonathan Woithe Cc: Darren Hart , Andy Shevchenko , platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 0/4] fujitsu_init() cleanup Message-ID: <20170306044905.GA3845@kmp-mobile.hq.kempniu.pl> References: <20170301081044.12141-1-kernel@kempniu.pl> <20170304014723.GA7944@marvin.atrad.com.au> <20170305234854.GG28473@marvin.atrad.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170305234854.GG28473@marvin.atrad.com.au> User-Agent: Mutt/1.8.0 (2017-02-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jonathan, Thanks for testing this series. > Hi Michael > > On Sat, Mar 04, 2017 at 12:17:23PM +1030, Jonathan Woithe wrote: > > On Wed, Mar 01, 2017 at 09:10:40AM +0100, Micha?? K??pie?? wrote: > > > These patches should make fujitsu_init() a bit more palatable. No > > > changes are made to platform device code yet, for clarity these will be > > > posted in a separate series after this one gets applied. > > > > I have a preliminary report. The backlight functionality remains functional > > on an S7020 across all four of the patches in this series and with the > > additional 2-patch cleanup series applied. > > > > With regard to patch 2/4 you wrote: > > > Jonathan, this *really* needs testing on relevant hardware. After > > > applying this patch, you should be able to turn LCD backlight on and off > > > using /sys/class/backlight/fujitsu-laptop/bl_power. Also, the value > > > returned by that attribute upon read should be in sync with actual > > > backlight state even right after loading the module (i.e. before writing > > > anything to bl_power). Please let me know if any of the above is not > > > true and the module works correctly without this patch applied. > > > > With patch 2/4 applied: > > > > * It is possible to read bl_power > > > > * It is possible to write a value to bl_power and read that value back > > > > * Writing values to bl_power does not appear to affect the LCD panel in > > any way. That is, the backlight remains unchanged regardless of the > > value written. > > > > * Behaviour is the same both under X and from the terminal. > > > > Backing out patch 2/4 but with all others still in place, resulted in no > > change in behaviour. So while bl_power had no effect with patch 2/4 in > > place, it seems that patch 2/4 is *not* the cause of this. > > > > I shall run some more bl_power tests and complete a review of the code later > > this weekend. > > I have completed a review of the code in this patch series (patches 1-4 of > 4) and can find no obvious problems. There do not appear to be any > regressions introduced by this patch series. As noted, patch 2/4 does not > provide working backlight power control on an S7020 but it may well be that > this has never been functional on the S7020 (I do not make use of bl_power > myself). > > I can add that immediately after loading the driver the value returned by a > read of bl_power is 0. As noted above, setting to 1 makes no difference to > the backlight, neither does returning it to 0. Have you tried setting bl_power to 4? Because that is the value of FB_BLANK_POWERDOWN, which is the value the patch is supposed to handle. > A value of 0 would normally > indicate that it's on I think, Yes, I believe so too as 0 corresponds to FB_BLANK_UNBLANK. > which means that the initial read of the > backlight power state does not appear to be working either. So I assume you have some kind of external display connected and the LCD backlight is off, correct? Just curious at this point. > As for the > other behaviour, this does not change if patch 2/4 is omitted. Commit 3a407086090b ("fujitsu-laptop: Add BL power, LED control and radio state information") which introduced backlight control mentions it was "tested on the S6420, P8010 & U810 platforms". Not sure if backlight control was tested on all these models and S7020 is not listed here, though I still find it puzzling that it did not work in the first place, i.e. without this series applied. This patch emerged from reading the DSDT table of a S7020, so I would expect backlight control to at least work properly through the "officially exposed" interface, i.e. FEXT. > Unfortunately I ran out of time over the weekend to cross check the > behaviour of bl_power on the S7020 with an unpatched kernel (as mentioned, I > don't utilise bl_power routinely myself and therefore can't recall whether > it has worked on my hardware in the past). For completeness I will try to > look at this sometime this week. However, given the patch content and the > observation that omitting patch 2/4 makes no difference to the S7020 > behaviour I am satisfied that at least on S7020 this patch series does not > introduce any regressions and represents a worthwhile clean up of the > driver's code. I would be happy to hear from someone for whom bl_power works as expected, though we really should not leave that backlight sync code where it currently is, so I am happy this is the conclusion you came to. > > I am happy to see this series applied in its entirety (including patch 2/4). > > Tested-by: Jonathan Woithe > Reviewed-by: Jonathan Woithe Thanks, -- Best regards, Michał Kępień