From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1FA14C04FEE for ; Wed, 20 Sep 2023 19:26:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 831B810E496; Wed, 20 Sep 2023 19:26:21 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTPS id 461F410E496; Wed, 20 Sep 2023 19:26:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1695237979; x=1726773979; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=xxqPkpxXDtBtEp+IYx3lyysaQQjIimZsAj+pY0FOX/M=; b=VjTbI2nT129D6eEwgv968z2TKn5rQBaAnksJ23KdHD2lkqmvRNjHX7kL U/25w1HpDpprVsT58p4kjitC1P+Ac00EgHOOiIkoamfcbqrohgMtOSR25 +QrPylOmNbJQZJ0OD6rlGRwH/km//71S+fqBjMlQRbA04+MhHL+kieCsV EeVqzPck1Cd1Rnm3GZY85XgvyhWeobeb4LcToclnNyauXYtwGSBDk7wLE c/f58GCG8wkQ44EjvXy/L3uCfeWL/4XIV3gW+rX6qSxT8p96A+Hpw/HJM +KZNUmqSQUeFVTQjrQISZWMNLtnHNY62jpCyGCPiRmk8aMFTIxhvogSD2 g==; X-IronPort-AV: E=McAfee;i="6600,9927,10839"; a="383063590" X-IronPort-AV: E=Sophos;i="6.03,162,1694761200"; d="scan'208";a="383063590" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Sep 2023 12:26:17 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10839"; a="862124113" X-IronPort-AV: E=Sophos;i="6.03,162,1694761200"; d="scan'208";a="862124113" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.153]) by fmsmga002.fm.intel.com with SMTP; 20 Sep 2023 12:26:14 -0700 Received: by stinkbox (sSMTP sendmail emulation); Wed, 20 Sep 2023 22:26:13 +0300 Date: Wed, 20 Sep 2023 22:26:13 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Jani Nikula Message-ID: References: <20230914112258.27156-1-ville.syrjala@linux.intel.com> <87jzskrbf3.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87jzskrbf3.fsf@intel.com> X-Patchwork-Hint: comment Subject: Re: [Intel-gfx] [PATCH] drm/edid: Fixup h/vsync_end instead of h/vtotal X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Wed, Sep 20, 2023 at 08:40:00PM +0300, Jani Nikula wrote: > On Thu, 14 Sep 2023, Ville Syrjala wrote: > > From: Ville Syrjälä > > > > There are some weird EDIDs floating around that have the sync > > pulse extending beyond the end of the blanking period. > > > > On the currently problemtic machine (HP Omni 120) EDID reports > > the following mode: > > "1600x900": 60 108000 1600 1780 1860 1800 900 910 913 1000 0x40 0x5 > > which is then "corrected" to have htotal=1861 by the current drm_edid.c > > code. > > > > The fixup code was originally added in commit 7064fef56369 ("drm: work > > around EDIDs with bad htotal/vtotal values"). Googling around we end up in > > https://bugs.launchpad.net/ubuntu/hardy/+source/xserver-xorg-video-intel/+bug/297245 > > where we find an EDID for a Dell Studio 15, which reports: > > (II) VESA(0): clock: 65.0 MHz Image Size: 331 x 207 mm > > (II) VESA(0): h_active: 1280 h_sync: 1328 h_sync_end 1360 h_blank_end 1337 h_border: 0 > > (II) VESA(0): v_active: 800 v_sync: 803 v_sync_end 809 v_blanking: 810 v_border: 0 > > > > Note that if we use the hblank size (as opposed of the hsync_end) > > from the DTD to determine htotal we get exactly 60Hz refresh rate in > > both cases, whereas using hsync_end to determine htotal we get a > > slightly lower refresh rates. This makes me believe the using the > > hblank size is what was intended even in those cases. > > > > Also note that in case of the HP Onmi 120 the VBIOS boots with these: > > crtc timings: 108000 1600 1780 1860 1800 900 910 913 1000, type: 0x40 flags: 0x5 > > ie. it just blindly stuffs the bogus hsync_end and htotal from the DTD > > into the transcoder timing registers, and the display works. I believe > > the (at least more modern) hardware will automagically terminate the hsync > > pulse when the timing generator reaches htotal, which again points that we > > should use the hblank size to determine htotal. Unfortunatley the old bug > > reports for the Dell machines are extremely lacking in useful details so > > we have no idea what kind of timings the VBIOS programmed into the > > hardware :( > > > > Let's just flip this quirk around and reduce the length of the sync > > pulse instead of extending the blanking period. This at least seems > > to be the correct thing to do on more modern hardware. And if any > > issues crop up on older hardware we need to debug them properly. > > > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8895 > > Signed-off-by: Ville Syrjälä > > --- > > drivers/gpu/drm/drm_edid.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c > > index 39dd3f694544..0c5563b4d21e 100644 > > --- a/drivers/gpu/drm/drm_edid.c > > +++ b/drivers/gpu/drm/drm_edid.c > > @@ -3497,11 +3497,11 @@ static struct drm_display_mode *drm_mode_detailed(struct drm_connector *connecto > > mode->vsync_end = mode->vsync_start + vsync_pulse_width; > > mode->vtotal = mode->vdisplay + vblank; > > > > - /* Some EDIDs have bogus h/vtotal values */ > > + /* Some EDIDs have bogus h/vsync_end values */ > > if (mode->hsync_end > mode->htotal) > > - mode->htotal = mode->hsync_end + 1; > > + mode->hsync_end = mode->htotal; > > if (mode->vsync_end > mode->vtotal) > > - mode->vtotal = mode->vsync_end + 1; > > + mode->vsync_end = mode->vtotal; > > I wonder if we shouldn't debug log these to help our future selves? Yeah, might be a good idea. I can respin with that. I noticed that our VBT parser has the exact same code in it as well so I'll be wanting to cook up a patch that as well. > > Anyway, > > Reviewed-by: Jani Nikula Ta. > > > > > > drm_mode_do_interlace_quirk(mode, pt); > > -- > Jani Nikula, Intel -- Ville Syrjälä Intel