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 DE7F3C04AB8 for ; Wed, 20 Sep 2023 17:40:18 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BCFF810E525; Wed, 20 Sep 2023 17:40:08 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTPS id B97AB10E517; Wed, 20 Sep 2023 17:40:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1695231605; x=1726767605; h=from:to:cc:subject:in-reply-to:references:date: message-id:mime-version:content-transfer-encoding; bh=uDX9/nqSC9pHxD0vJh8X6LLyWdaKxMDcJfC+wR/V9q4=; b=NXwfJkHMOaBxNlFDFROK7y3BUbhikqgVtA0gwumWAqXXtiQZjvfuuzCL gLcBpgVsOX6GXKOBAHLpO0+FUbRgR7ZKYcM5TSNApfNlC9UB5yzcipl3W gPrDeLkXKjZJHvBexg4PtRnZrat7Ke3RPsBmYtVTrm/dbVdf3tpoiPaom o1oVCMY+LGFAe6Sjbv0i/lrCW4x1cGgHQXYAPeSetCQgxyVZA+yDU7eQy GiNburOrzCPtKxiTPIbNgpn4BuTHFi4OuL/bgnU9YRWufJqQl3T17XeNt hh5Qj88jnd9vIMVba4KiMyPqF/kFXEOehhx/v93iEW3NC3AAsHFRo9G5B A==; X-IronPort-AV: E=McAfee;i="6600,9927,10839"; a="379178407" X-IronPort-AV: E=Sophos;i="6.03,162,1694761200"; d="scan'208";a="379178407" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Sep 2023 10:40:04 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10839"; a="890021035" X-IronPort-AV: E=Sophos;i="6.03,162,1694761200"; d="scan'208";a="890021035" Received: from ptelkov-mobl2.ccr.corp.intel.com (HELO localhost) ([10.252.38.103]) by fmsmga001-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Sep 2023 10:39:14 -0700 From: Jani Nikula To: Ville Syrjala , dri-devel@lists.freedesktop.org In-Reply-To: <20230914112258.27156-1-ville.syrjala@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20230914112258.27156-1-ville.syrjala@linux.intel.com> Date: Wed, 20 Sep 2023 20:40:00 +0300 Message-ID: <87jzskrbf3.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable 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 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, 14 Sep 2023, Ville Syrjala wrote: > From: Ville Syrj=C3=A4l=C3=A4 > > 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=3D1861 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 1= 337 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 f= lags: 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 Syrj=C3=A4l=C3=A4 > --- > 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 =3D mode->vsync_start + vsync_pulse_width; > mode->vtotal =3D mode->vdisplay + vblank; >=20=20 > - /* Some EDIDs have bogus h/vtotal values */ > + /* Some EDIDs have bogus h/vsync_end values */ > if (mode->hsync_end > mode->htotal) > - mode->htotal =3D mode->hsync_end + 1; > + mode->hsync_end =3D mode->htotal; > if (mode->vsync_end > mode->vtotal) > - mode->vtotal =3D mode->vsync_end + 1; > + mode->vsync_end =3D mode->vtotal; I wonder if we shouldn't debug log these to help our future selves? Anyway, Reviewed-by: Jani Nikula >=20=20 > drm_mode_do_interlace_quirk(mode, pt); --=20 Jani Nikula, Intel