From: Steven Rostedt <rostedt@goodmis.org>
To: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Hans de Goede <hdegoede@redhat.com>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
Petr Mladek <pmladek@suse.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 2/3] fbcon: Call WARN_CONSOLE_UNLOCKED() where applicable
Date: Wed, 11 Jul 2018 10:52:55 -0400 [thread overview]
Message-ID: <20180711105255.32803a3c@gandalf.local.home> (raw)
In-Reply-To: <717e6337-e7a6-7a92-1c1b-8929a25696b5@suse.de>
On Wed, 11 Jul 2018 16:46:11 +0200
Thomas Zimmermann <tzimmermann@suse.de> wrote:
> Hi
>
> Am 28.06.2018 um 11:03 schrieb Hans de Goede:
> > Replace comments about places where the console lock should be held with
> > calls to WARN_CONSOLE_UNLOCKED() to assert that it is actually held.
>
> Debugging fbcon sometimes requires to not take the console lock. This
> patch breaks the debugging workaround provided by
> 'fb.lockless_register_fb'. The dmesg is now filled with warnings about
> the missing lock.
>
What if you make lockless_register_fb visible to fbcon, and then we can
have a macro:
#define WARN_FB_CONSOLE_UNLOCKED() \
do { \
if (unlikely(!lockless_register_fb)) \
WARN_CONSOLE_UNLOCKED(); \
} while (0)
And use that instead?
-- Steve
> Best regards
> Thomas
>
> > Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> > Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> > Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
> > Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> > ---
> > Changes in v3:
> > -New patch in v3 of this patchset
> >
> > Changes in v4:
> > -Keep the comments about which fbcon functions need locks in place
> > ---
> > drivers/video/fbdev/core/fbcon.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/video/fbdev/core/fbcon.c b/drivers/video/fbdev/core/fbcon.c
> > index c910e74d46ff..cd8d52a967aa 100644
> > --- a/drivers/video/fbdev/core/fbcon.c
> > +++ b/drivers/video/fbdev/core/fbcon.c
> > @@ -828,6 +828,8 @@ static int set_con2fb_map(int unit, int newidx, int user)
> > struct fb_info *oldinfo = NULL;
> > int found, err = 0;
> >
> > + WARN_CONSOLE_UNLOCKED();
> > +
> > if (oldidx == newidx)
> > return 0;
> >
> > @@ -3044,6 +3046,8 @@ static int fbcon_fb_unbind(int idx)
> > {
> > int i, new_idx = -1, ret = 0;
> >
> > + WARN_CONSOLE_UNLOCKED();
> > +
> > if (!fbcon_has_console_bind)
> > return 0;
> >
> > @@ -3094,6 +3098,8 @@ static int fbcon_fb_unregistered(struct fb_info *info)
> > {
> > int i, idx;
> >
> > + WARN_CONSOLE_UNLOCKED();
> > +
> > idx = info->node;
> > for (i = first_fb_vc; i <= last_fb_vc; i++) {
> > if (con2fb_map[i] == idx)
> > @@ -3131,6 +3137,9 @@ static int fbcon_fb_unregistered(struct fb_info *info)
> > static void fbcon_remap_all(int idx)
> > {
> > int i;
> > +
> > + WARN_CONSOLE_UNLOCKED();
> > +
> > for (i = first_fb_vc; i <= last_fb_vc; i++)
> > set_con2fb_map(i, idx, 0);
> >
> > @@ -3177,6 +3186,8 @@ static int fbcon_fb_registered(struct fb_info *info)
> > {
> > int ret = 0, i, idx;
> >
> > + WARN_CONSOLE_UNLOCKED();
> > +
> > idx = info->node;
> > fbcon_select_primary(info);
> >
>
next prev parent reply other threads:[~2018-07-11 14:53 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20180628090357epcas5p28361ab4b3ce11c179a167548f4851983@epcas5p2.samsung.com>
2018-06-28 9:03 ` [PATCH v5 0/3] console/fbcon: Add support for deferred console takeover Hans de Goede
2018-06-28 9:03 ` [PATCH v5 1/3] printk: Export is_console_locked Hans de Goede
2018-06-28 9:03 ` [PATCH v5 2/3] fbcon: Call WARN_CONSOLE_UNLOCKED() where applicable Hans de Goede
2018-07-11 14:46 ` Thomas Zimmermann
2018-07-11 14:52 ` Steven Rostedt [this message]
2018-07-11 15:01 ` Hans de Goede
2018-07-11 15:07 ` Daniel Vetter
2018-07-11 15:07 ` Thomas Zimmermann
2018-07-11 15:14 ` Hans de Goede
2018-07-11 15:28 ` Daniel Vetter
2018-07-11 15:35 ` Hans de Goede
2018-07-11 15:41 ` Steven Rostedt
2018-07-11 15:42 ` Daniel Vetter
2018-07-11 17:35 ` Hans de Goede
2018-07-11 17:56 ` Daniel Vetter
2018-07-11 19:19 ` Steven Rostedt
2018-07-11 19:41 ` Hans de Goede
2018-07-12 10:16 ` Thomas Zimmermann
2018-07-11 23:59 ` Sergey Senozhatsky
2018-06-28 9:03 ` [PATCH v5 3/3] console/fbcon: Add support for deferred console takeover Hans de Goede
2018-07-03 16:13 ` Sergey Senozhatsky
2018-07-03 16:14 ` Steven Rostedt
2018-07-03 16:36 ` Sergey Senozhatsky
2018-06-28 13:50 ` [PATCH v5 0/3] " Bartlomiej Zolnierkiewicz
2018-06-28 15:24 ` Hans de Goede
2018-06-28 22:44 ` Gustavo Padovan
2018-06-29 10:08 ` Bartlomiej Zolnierkiewicz
2018-06-29 12:51 ` Gustavo Padovan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180711105255.32803a3c@gandalf.local.home \
--to=rostedt@goodmis.org \
--cc=b.zolnierkie@samsung.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=hdegoede@redhat.com \
--cc=linux-fbdev@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pmladek@suse.com \
--cc=sergey.senozhatsky@gmail.com \
--cc=tzimmermann@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).