From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756188Ab2D3LBc (ORCPT ); Mon, 30 Apr 2012 07:01:32 -0400 Received: from mail-vx0-f174.google.com ([209.85.220.174]:50381 "EHLO mail-vx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752348Ab2D3LBb convert rfc822-to-8bit (ORCPT ); Mon, 30 Apr 2012 07:01:31 -0400 MIME-Version: 1.0 In-Reply-To: References: <20120422164023.GA32342@elliptictech.com> <20120423000554.GA893@elliptictech.com> <20120423024558.GD13840@phenom.dumpdata.com> <20120424010345.GA30674@elliptictech.com> <20120425013537.GA11959@elliptictech.com> <1335322574.1821.8.camel@nisroch> <1335504021.5311.0.camel@nisroch> <20120428003928.GA16805@elliptictech.com> <20120428153350.GA19561@elliptictech.com> <20120429223744.GA19382@core.coreip.homeip.net> Date: Mon, 30 Apr 2012 13:01:30 +0200 Message-ID: Subject: Re: Linux 3.4-rc4 From: Luca Tettamanti To: Maarten Maathuis Cc: Dmitry Torokhov , Nick Bowler , Martin Peres , Linus Torvalds , Linux Kernel Mailing List , dri-devel@lists.freedesktop.org, Jean Delvare Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 30, 2012 at 11:07 AM, Maarten Maathuis wrote: > On Mon, Apr 30, 2012 at 12:37 AM, Dmitry Torokhov > wrote: >> On Sat, Apr 28, 2012 at 11:33:50AM -0400, Nick Bowler wrote: >>> On 2012-04-28 02:19 -0400, Alex Deucher wrote: >>> > On Fri, Apr 27, 2012 at 8:39 PM, Nick Bowler wrote: >>> > > Hi Ben, >>> > > >>> > > On 2012-04-27 15:20 +1000, Ben Skeggs wrote: >>> > >> Does this patch help you at all? >>> > >> >>> > >> http://cgit.freedesktop.org/nouveau/linux-2.6/commit/?id=a3a285f17867f0018de798b5ee85731ec1268305 >>> > > >>> > > Yes.  I cherry-picked this patch on top of Linus' master (3.4-rc4+) and >>> > > this appears to solve the "black screen on VGA" problem described in the >>> > > original report.  Thanks! >>> > > >>> > > Unfortunately, that's not the end of my VGA-related regressions. :( >>> > > >>> > > While tracking down the black screen issue, I've been having the monitor >>> > > directly connected to the video card the whole time, but now when I'm >>> > > connected through my KVM switch (an IOGear GCS1804), it appears that >>> > > something's going wrong with reading the EDID, because the available >>> > > modes are all screwed up (both console and X decide they want to drive >>> > > the display at 1024x768).  Here's the output of xrandr on 3.2.15: >>> > > >>> > >  % xrandr >>> > >  Screen 1: minimum 320 x 200, current 1600 x 1200, maximum 4096 x 4096 >>> > >  VGA-1 connected 1600x1200+0+0 (normal left inverted right x axis y axis) 352mm x 264mm >>> > >     1600x1200      75.0*+   70.0     65.0     60.0 >>> > >     1280x1024      85.0 +   75.0     60.0 >>> > >     1920x1440      60.0 >>> > >     1856x1392      60.0 >>> > >     1792x1344      60.0 >>> > >     1920x1200      74.9     59.9 >>> > >     1680x1050      84.9     74.9     60.0 >>> > >     1400x1050      85.0     74.9     60.0 >>> > >     1440x900       84.8     75.0     59.9 >>> > >     1280x960       85.0     60.0 >>> > >     1360x768       60.0 >>> > >     1280x800       84.9     74.9     59.8 >>> > >     1152x864       75.0 >>> > >     1280x768       84.8     74.9     59.9 >>> > >     1024x768       85.0     75.1     75.0     70.1     60.0     43.5     43.5 >>> > >     832x624        74.6 >>> > >     800x600        85.1     72.2     75.0     60.3     56.2 >>> > >     848x480        60.0 >>> > >     640x480        85.0     75.0     72.8     72.8     66.7     60.0     59.9 >>> > >     720x400        85.0     87.8     70.1 >>> > >     640x400        85.1 >>> > >     640x350        85.1 >>> > >     320x200       165.1 >>> > > >>> > > And on 3.4-rc4+ (with your patch cherry-picked): >>> > > >>> > >  % xrandr >>> > >  Screen 1: minimum 320 x 200, current 1024 x 768, maximum 4096 x 4096 >>> > >  VGA-1 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm >>> > >     1024x768       60.0* >>> > >     800x600        60.3     56.2 >>> > >     848x480        60.0 >>> > >     640x480        59.9 >>> > >     320x200       165.1 >>> > > >>> > > Running xrandr on 3.4-rc4+ also causes the screen to go black for a >>> > > second when it does not on 3.2.15.  It also causes several messages of >>> > > the form >>> > > >>> > >  [drm] nouveau 0000:01:00.0: Load detected on output B >>> > > >>> > > to be logged.  Also, looking at /sys/class/drm/card0-VGA-1/edid I see >>> > > that it is empty on 3.4-rc4+ and it is correct on 3.2.15.  Things seem >>> > > to work OK when the KVM is not involved. >>> > >>> > Were you ever able to fetch a EDID with the KVM involved?  KVMs are >>> > notorious for not connecting the ddc pins. >>> >>> Yes, it works on 3.2.15 as described above. >> >> I have the same (or similar) KVM (not in the office at the moment) and I >> can confirm that with newer kernels EDID fecthing in flaky. It's 50/50 >> if EDED retrieval succeeds or if it fails with: >> >> Apr 26 13:06:57 dtor-d630 kernel: [13464.936336] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 208 >> Apr 26 13:06:57 dtor-d630 kernel: [13464.955317] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 208 >> Apr 26 13:06:57 dtor-d630 kernel: [13464.973879] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 208 >> Apr 27 09:13:03 dtor-d630 kernel: [44602.087659] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 208 >> Apr 27 09:13:03 dtor-d630 kernel: [44602.107147] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 208 >> Apr 27 09:13:03 dtor-d630 kernel: [44602.126908] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 208 >> Apr 27 09:13:03 dtor-d630 kernel: [44602.146277] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 208 >> Apr 27 09:13:03 dtor-d630 kernel: [44602.297659] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 208 >> Apr 27 09:13:03 dtor-d630 kernel: [44602.317063] [drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 208 >> >> Earlier kernels were able to retrieve EDEDs reliably. >> >> This is with: >> >> [    1.678392] [drm] nouveau 0000:01:00.0: Detected an NV50 generation card (0x086b00a2) > > Just a crazy thought, but didn't we change some timings related to > EDID retrieval? To make it faster. Hum, this commit: commit 1849ecb22fb3b5d57b65e7369a3957adf9f26f39 Author: Jean Delvare Date: Sat Jan 28 11:07:09 2012 +0100 drm/kms: Make i2c buses faster doubled the data rate but only for radeon and intel drivers. nouveau doesn't use the standard i2c-algo-bit helpers (BTW: the cond_resched() has been removed), and AFAICS it's using 1us delay; the other drivers are using 10us, 1us seems a bit too low... Luca