[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20190710140504.t5lsk36gnn5cdn6b@flea>
Date: Wed, 10 Jul 2019 16:05:04 +0200
From: Maxime Ripard <maxime.ripard@...tlin.com>
To: Dmitry Osipenko <digetx@...il.com>
Cc: Thierry Reding <thierry.reding@...il.com>,
Jonathan Hunter <jonathanh@...dia.com>,
Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
Sean Paul <sean@...rly.run>, Daniel Vetter <daniel@...ll.ch>,
David Airlie <airlied@...ux.ie>,
dri-devel@...ts.freedesktop.org, linux-tegra@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1] drm/modes: Skip invalid cmdline mode
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?
Maxime
--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
Download attachment "signature.asc" of type "application/pgp-signature" (229 bytes)
Powered by blists - more mailing lists