From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [PATCH v1] drm/modes: Skip invalid cmdline mode Date: Wed, 10 Jul 2019 18:05:18 +0300 Message-ID: References: <20190709145151.23086-1-digetx@gmail.com> <20190710101229.54ufuhmh22dfxclr@flea> <4ad69d15-07f8-9753-72d6-a51402c94c20@gmail.com> <20190710125552.qvmnh6qs63ikiu2k@flea> <20190710130615.gvi2jwgr2cds66xr@flea> <75719cad-c65c-7ebc-3ea8-98134f86ddc3@gmail.com> <4a13f12f-05a7-473e-4e4e-7a7e32d09720@gmail.com> <20190710140504.t5lsk36gnn5cdn6b@flea> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190710140504.t5lsk36gnn5cdn6b@flea> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Maxime Ripard Cc: Thierry Reding , Jonathan Hunter , Maarten Lankhorst , Sean Paul , Daniel Vetter , David Airlie , dri-devel@lists.freedesktop.org, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org 10.07.2019 17:05, Maxime Ripard пишет: > On Wed, Jul 10, 2019 at 04:29:19PM +0300, Dmitry Osipenko wrote: >> This works: >> >> diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c >> index 56d36779d213..e5a2f9c8f404 100644 >> --- a/drivers/gpu/drm/drm_client_modeset.c >> +++ b/drivers/gpu/drm/drm_client_modeset.c >> @@ -182,6 +182,8 @@ drm_connector_pick_cmdline_mode(struct drm_connector *connector) >> mode = drm_mode_create_from_cmdline_mode(connector->dev, cmdline_mode); >> if (mode) >> list_add(&mode->head, &connector->modes); >> + else >> + cmdline_mode->specified = false; > > Hmmm, it's not clear to me why that wouldn't be the case. > > If we come back to the beginning of that function, we retrieve the > cmdline_mode buffer from the connector pointer, that will probably > have been parsed a first time using drm_mode_create_from_cmdline_mode > in drm_helper_probe_add_cmdline_mode. > > Now, I'm guessing that the issue is that in > drm_mode_parse_command_line_for_connector, if we have a named mode, we > just copy the mode over and set mode->specified. > > And we then move over to do other checks, and that's probably what > fails and returns, but our drm_cmdline_mode will have been modified. > > I'm not entirely sure how to deal with that though. > > I guess we could allocate a drm_cmdline_mode structure on the stack, > fill that, and if successful copy over its content to the one in > drm_connector. That would allow us to only change the content on > success, which is what I would expect from such a function? > > How does that sound? I now see that there is DRM_MODE_TYPE_USERDEF flag that is assigned only for the "cmdline" mode and drm_client_rotation() is the only place in DRM code that cares about whether mode is from cmdline, hence looks like it will be more correct to do the following: diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c index 56d36779d213..e5b3be9ed689 100644 --- a/drivers/gpu/drm/drm_client_modeset.c +++ b/drivers/gpu/drm/drm_client_modeset.c @@ -825,6 +825,7 @@ bool drm_client_rotation(struct drm_mode_set *modeset, unsigned int *rotation) { struct drm_connector *connector = modeset->connectors[0]; struct drm_plane *plane = modeset->crtc->primary; + struct drm_display_mode *mode = modeset->mode; struct drm_cmdline_mode *cmdline; u64 valid_mask = 0; unsigned int i; @@ -859,7 +860,7 @@ bool drm_client_rotation(struct drm_mode_set *modeset, unsigned int *rotation) * simple XOR between the two handle the addition nicely. */ cmdline = &connector->cmdline_mode; - if (cmdline->specified) { + if (mode->flags & DRM_MODE_TYPE_USERDEF) { unsigned int cmdline_rest, panel_rest; unsigned int cmdline_rot, panel_rot; unsigned int sum_rot, sum_rest;