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 17:03:23 +0300 Message-ID: <73d5dcd7-adef-8844-4e13-a68a0a5db98a@gmail.com> References: <20190709145151.23086-1-digetx@gmail.com> <20190710100000.GZ5942@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190710100000.GZ5942@intel.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= Cc: Thierry Reding , Jonathan Hunter , Maarten Lankhorst , Maxime Ripard , Sean Paul , Daniel Vetter , David Airlie , linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org List-Id: linux-tegra@vger.kernel.org 10.07.2019 13:00, Ville Syrjälä пишет: > On Tue, Jul 09, 2019 at 05:51:51PM +0300, Dmitry Osipenko wrote: >> The named mode could be invalid and then cmdline parser misses to validate >> mode's dimensions, happily adding 0x0 mode as a valid mode. One case where >> this happens is NVIDIA Tegra devices that are using downstream bootloader >> which adds "video=tegrafb" to the kernel's cmdline and thus upstream Tegra >> DRM driver fails to probe because of the invalid mode. >> >> Fixes: 3aeeb13d8996 ("drm/modes: Support modes names on the command line") > > Is that actually true? This problem has been in the code since forever AFAICS. Yes, it's a problem now because named mode is marked as specified and everything that do not match to a non-named mode is treated as named. >> Signed-off-by: Dmitry Osipenko >> --- >> drivers/gpu/drm/drm_client_modeset.c | 3 ++- >> drivers/gpu/drm/drm_modes.c | 6 ++++++ >> 2 files changed, 8 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/drm_client_modeset.c b/drivers/gpu/drm/drm_client_modeset.c >> index e95fceac8f8b..56d36779d213 100644 >> --- a/drivers/gpu/drm/drm_client_modeset.c >> +++ b/drivers/gpu/drm/drm_client_modeset.c >> @@ -180,7 +180,8 @@ drm_connector_pick_cmdline_mode(struct drm_connector *connector) >> >> create_mode: >> mode = drm_mode_create_from_cmdline_mode(connector->dev, cmdline_mode); >> - list_add(&mode->head, &connector->modes); >> + if (mode) >> + list_add(&mode->head, &connector->modes); > > That's the same as what I did here > https://patchwork.freedesktop.org/patch/309223/?series=61781&rev=1 > > But I'd have to rebase that so let's just go with your patch. > >> >> return mode; >> } >> diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c >> index 910561d4f071..74a5739df506 100644 >> --- a/drivers/gpu/drm/drm_modes.c >> +++ b/drivers/gpu/drm/drm_modes.c >> @@ -158,6 +158,9 @@ struct drm_display_mode *drm_cvt_mode(struct drm_device *dev, int hdisplay, >> int interlace; >> u64 tmp; >> >> + if (!hdisplay || !vdisplay) >> + return NULL; >> + >> /* allocate the drm_display_mode structure. If failure, we will >> * return directly >> */ >> @@ -392,6 +395,9 @@ drm_gtf_mode_complex(struct drm_device *dev, int hdisplay, int vdisplay, >> int hsync, hfront_porch, vodd_front_porch_lines; >> unsigned int tmp1, tmp2; >> >> + if (!hdisplay || !vdisplay) >> + return NULL; >> + > > These lgtm > > Patch is > Reviewed-by: Ville Syrjälä Thanks!