From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga01.intel.com ([192.55.52.88]:44836 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751415AbcFAJn7 (ORCPT ); Wed, 1 Jun 2016 05:43:59 -0400 Date: Wed, 1 Jun 2016 12:43:53 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Chris Wilson Cc: dri-devel@lists.freedesktop.org, Radek =?iso-8859-1?Q?Dost=E1l?= , Jesse Barnes , Daniel Vetter , Julia Lemire , Dave Airlie , stable@vger.kernel.org Subject: Re: [PATCH v3] drm: Only create a cmdline mode if no probed modes match Message-ID: <20160601094353.GC4329@intel.com> References: <1429532795-3922-1-git-send-email-chris@chris-wilson.co.uk> <1464773676-20152-1-git-send-email-chris@chris-wilson.co.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1464773676-20152-1-git-send-email-chris@chris-wilson.co.uk> Sender: stable-owner@vger.kernel.org List-ID: On Wed, Jun 01, 2016 at 10:34:36AM +0100, Chris Wilson wrote: > The intention of using video=: is primarily to select > the user's preferred resolution at startup. Currently we always create a > new mode irrespective of whether the monitor has a native mode at the > desired resolution. This has the issue that we may then select the fake > mode rather the native mode during fb_helper->inital_config() and so > if the fake mode is invalid we then end up with a loss of signal. Oops. > This invalid fake mode would also be exported to userspace, who > potentially may make the same mistake. > > To avoid this issue, we filter out the added command line mode if we > detect the desired resolution (and clock if specified) amongst the > probed modes. This fixes the immediate problem of adding a duplicate > mode, but perhaps more generically we should avoid adding a GTF mode if > the monitor has an EDID that is not GTF-compatible, or similarly for > CVT. > > Fixes regression from > > commit eaf99c749d43ae74ac7ffece5512f3c73f01dfd2 > Author: Chris Wilson > Date: Wed Aug 6 10:08:32 2014 +0200 > > drm: Perform cmdline mode parsing during connector initialisation > > that breaks HDMI output on BeagleBone Black with LG TV (model 19LS4R-ZA). > > v2: Explicitly delete our earlier cmdline mode > v3: Mode pruning should now be sufficient to delete stale cmdline modes > > Reported-by: Radek Dost�l > Signed-off-by: Chris Wilson > Cc: Radek Dost�l > Cc: Jesse Barnes > Cc: Ville Syrj�l� > Cc: Daniel Vetter > Cc: dri-devel@lists.freedesktop.org > Cc: Julia Lemire > Cc: Dave Airlie > Cc: stable@vger.kernel.org > --- > drivers/gpu/drm/drm_probe_helper.c | 19 +++++++++++++++++-- > 1 file changed, 17 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c > index 0329080d7f7c..a705ed12c062 100644 > --- a/drivers/gpu/drm/drm_probe_helper.c > +++ b/drivers/gpu/drm/drm_probe_helper.c > @@ -82,13 +82,28 @@ drm_mode_validate_flag(const struct drm_display_mode *mode, > > static int drm_helper_probe_add_cmdline_mode(struct drm_connector *connector) > { > + struct drm_cmdline_mode *cmdline_mode; > struct drm_display_mode *mode; > > - if (!connector->cmdline_mode.specified) > + cmdline_mode = &connector->cmdline_mode; > + if (!cmdline_mode->specified) > return 0; > > + /* Only add a GTF mode if we find no matching probed modes */ > + list_for_each_entry(mode, &connector->probed_modes, head) { > + if (mode->hdisplay != cmdline_mode->xres || > + mode->vdisplay != cmdline_mode->yres) > + continue; > + > + if (cmdline_mode->refresh_specified && > + mode->vrefresh != cmdline_mode->refresh) I think we might not have .vrefresh populated for the probed modes. We update .vrefresh only for the modes left on the real mode list in the end. > + continue; > + > + return 0; > + } > + > mode = drm_mode_create_from_cmdline_mode(connector->dev, > - &connector->cmdline_mode); > + cmdline_mode); > if (mode == NULL) > return 0; > > -- > 2.8.1 -- Ville Syrj�l� Intel OTC