| Message ID | 20180628090351.15581-3-hdegoede@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
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. 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); >
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); > > > -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, On 11-07-18 16:52, Steven Rostedt wrote: > 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? Yes I'm already preparing a patch like that :) Without the unlikely though, this is not used in hot paths. Regards, Hans > > -- 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); >>> >> > -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Am 11.07.2018 um 16:52 schrieb Steven Rostedt: > > What if you make lockless_register_fb visible to fbcon, and then we can > have a macro: There are more of these macro invocations under drivers/tty/vt, which also mess up the log during debugging. WARN_CONSOLE_UNLOCKED is already protected by an '#ifdef 1 ... #else ...' construct [1]. I thought about turning this into a config option. Best regards Thomas [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/console.h#n203 > > #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); >>> >> >
On Wed, Jul 11, 2018 at 5:01 PM, Hans de Goede <hdegoede@redhat.com> wrote: > Hi, > > On 11-07-18 16:52, Steven Rostedt wrote: >> >> 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? > > > Yes I'm already preparing a patch like that :) > > Without the unlikely though, this is not used in hot paths. Note that you don't even need an EXPORT_SYMBOL since this is all in the same module. -Daniel > Regards, > > Hans > > > > >> >> -- 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); >>>> >>> >>> >> > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
Hi, On 11-07-18 17:07, Thomas Zimmermann wrote: > Hi > > Am 11.07.2018 um 16:52 schrieb Steven Rostedt: >> >> What if you make lockless_register_fb visible to fbcon, and then we can >> have a macro: > > There are more of these macro invocations under drivers/tty/vt, which > also mess up the log during debugging. Hmm, so this option is already broken (in a way) then, my first reaction to your mail was that we should just remove that option. But that seemed a bit harsh to me so I've been working on a fix for the last 10 minutes or so. But if it is already broken I'm tempted to just remove the option and be done with it. We really need less cruft in the fbdev/fbcon code not more. > WARN_CONSOLE_UNLOCKED is already protected by an '#ifdef 1 ... #else > ...' construct [1]. I thought about turning this into a config option. Ah I noticed the #if but I did not notice that it was a "#if 1". If you want to fix lockless_register_fb it really should be replaced with a runtime check, not a Kconfig option. This would require having some lockless variable in the console code itself, which then gets set by the fbdev code during init based on its lockless_register_fb setting. But as said I think we should seriously consider just removing lockless_register_fb. Regards, Hans > > Best regards > Thomas > > [1] > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/console.h#n203 > >> >> #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); >>>> >>> >> > -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jul 11, 2018 at 5:14 PM, Hans de Goede <hdegoede@redhat.com> wrote: > Hi, > > On 11-07-18 17:07, Thomas Zimmermann wrote: >> >> Hi >> >> Am 11.07.2018 um 16:52 schrieb Steven Rostedt: >>> >>> >>> What if you make lockless_register_fb visible to fbcon, and then we can >>> have a macro: >> >> >> There are more of these macro invocations under drivers/tty/vt, which >> also mess up the log during debugging. > > > Hmm, so this option is already broken (in a way) then, my first reaction > to your mail was that we should just remove that option. But that seemed > a bit harsh to me so I've been working on a fix for the last 10 minutes > or so. > > But if it is already broken I'm tempted to just remove the option and > be done with it. We really need less cruft in the fbdev/fbcon code not > more. Please don't remove it, it makes debugging kms driver issues on initial modeset (which is usually run from framebuffer_register, while hodling the console_lock) impossible. -Daniel >> WARN_CONSOLE_UNLOCKED is already protected by an '#ifdef 1 ... #else >> ...' construct [1]. I thought about turning this into a config option. > > > Ah I noticed the #if but I did not notice that it was a "#if 1". > > If you want to fix lockless_register_fb it really should be replaced > with a runtime check, not a Kconfig option. This would require having > some lockless variable in the console code itself, which then gets > set by the fbdev code during init based on its lockless_register_fb > setting. > > But as said I think we should seriously consider just removing > lockless_register_fb. > > Regards, > > Hans > > > > > > > >> >> Best regards >> Thomas >> >> [1] >> >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/console.h#n203 >> >>> >>> #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); >>>>> >>>> >>>> >>> >> > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
Hi, On 11-07-18 17:28, Daniel Vetter wrote: > On Wed, Jul 11, 2018 at 5:14 PM, Hans de Goede <hdegoede@redhat.com> wrote: >> Hi, >> >> On 11-07-18 17:07, Thomas Zimmermann wrote: >>> >>> Hi >>> >>> Am 11.07.2018 um 16:52 schrieb Steven Rostedt: >>>> >>>> >>>> What if you make lockless_register_fb visible to fbcon, and then we can >>>> have a macro: >>> >>> >>> There are more of these macro invocations under drivers/tty/vt, which >>> also mess up the log during debugging. >> >> >> Hmm, so this option is already broken (in a way) then, my first reaction >> to your mail was that we should just remove that option. But that seemed >> a bit harsh to me so I've been working on a fix for the last 10 minutes >> or so. >> >> But if it is already broken I'm tempted to just remove the option and >> be done with it. We really need less cruft in the fbdev/fbcon code not >> more. > > Please don't remove it, it makes debugging kms driver issues on > initial modeset (which is usually run from framebuffer_register, while > hodling the console_lock) impossible. OK, so if we don't remove it, we should probably make it so that it can be used without triggering any WARN_ONs, which would require changing the existing WARN_CONSOLE_UNLOCKED() so that the calls from drivers/tty/vt/vt.c also do not trigger it ? I guess one can just ignore the oopses when debugging, but debugging surely would be easier if there are just no oopses ? Regards, Hans > -Daniel > >>> WARN_CONSOLE_UNLOCKED is already protected by an '#ifdef 1 ... #else >>> ...' construct [1]. I thought about turning this into a config option. >> >> >> Ah I noticed the #if but I did not notice that it was a "#if 1". >> >> If you want to fix lockless_register_fb it really should be replaced >> with a runtime check, not a Kconfig option. This would require having >> some lockless variable in the console code itself, which then gets >> set by the fbdev code during init based on its lockless_register_fb >> setting. >> >> But as said I think we should seriously consider just removing >> lockless_register_fb. >> >> Regards, >> >> Hans >> >> >> >> >> >> >> >>> >>> Best regards >>> Thomas >>> >>> [1] >>> >>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/console.h#n203 >>> >>>> >>>> #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); >>>>>> >>>>> >>>>> >>>> >>> >> _______________________________________________ >> dri-devel mailing list >> dri-devel@lists.freedesktop.org >> https://lists.freedesktop.org/mailman/listinfo/dri-devel > > > -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jul 11, 2018 at 5:35 PM, Hans de Goede <hdegoede@redhat.com> wrote: > Hi, > > On 11-07-18 17:28, Daniel Vetter wrote: >> >> On Wed, Jul 11, 2018 at 5:14 PM, Hans de Goede <hdegoede@redhat.com> >> wrote: >>> >>> Hi, >>> >>> On 11-07-18 17:07, Thomas Zimmermann wrote: >>>> >>>> >>>> Hi >>>> >>>> Am 11.07.2018 um 16:52 schrieb Steven Rostedt: >>>>> >>>>> >>>>> >>>>> What if you make lockless_register_fb visible to fbcon, and then we can >>>>> have a macro: >>>> >>>> >>>> >>>> There are more of these macro invocations under drivers/tty/vt, which >>>> also mess up the log during debugging. >>> >>> >>> >>> Hmm, so this option is already broken (in a way) then, my first reaction >>> to your mail was that we should just remove that option. But that seemed >>> a bit harsh to me so I've been working on a fix for the last 10 minutes >>> or so. >>> >>> But if it is already broken I'm tempted to just remove the option and >>> be done with it. We really need less cruft in the fbdev/fbcon code not >>> more. >> >> >> Please don't remove it, it makes debugging kms driver issues on >> initial modeset (which is usually run from framebuffer_register, while >> hodling the console_lock) impossible. > > > OK, so if we don't remove it, we should probably make it so that it > can be used without triggering any WARN_ONs, which would require changing > the existing WARN_CONSOLE_UNLOCKED() so that the calls from > drivers/tty/vt/vt.c > also do not trigger it ? > > I guess one can just ignore the oopses when debugging, but debugging surely > would be easier if there are just no oopses ? I'd say let's only bother with the ones in fbcon.c. Avoids the trouble with having to expose the fb module option to vt.c somehow. The ones in vt.c are as old as the git history (from a quick check at least), and in my debugging they never have been annoying (or I somehow didn't ever hit them, not idea). Also note that none if this matters long-term because I have a really fancy plan to fix up this entire console_locking mess, which will also remove the need for the lockless_fb_register debug hack. -Daniel > > Regards, > > Hans > > > > > >> -Daniel >> >>>> WARN_CONSOLE_UNLOCKED is already protected by an '#ifdef 1 ... #else >>>> ...' construct [1]. I thought about turning this into a config option. >>> >>> >>> >>> Ah I noticed the #if but I did not notice that it was a "#if 1". >>> >>> If you want to fix lockless_register_fb it really should be replaced >>> with a runtime check, not a Kconfig option. This would require having >>> some lockless variable in the console code itself, which then gets >>> set by the fbdev code during init based on its lockless_register_fb >>> setting. >>> >>> But as said I think we should seriously consider just removing >>> lockless_register_fb. >>> >>> Regards, >>> >>> Hans >>> >>> >>> >>> >>> >>> >>> >>>> >>>> Best regards >>>> Thomas >>>> >>>> [1] >>>> >>>> >>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/console.h#n203 >>>> >>>>> >>>>> #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); >>>>>>> >>>>>> >>>>>> >>>>> >>>> >>> _______________________________________________ >>> dri-devel mailing list >>> dri-devel@lists.freedesktop.org >>> https://lists.freedesktop.org/mailman/listinfo/dri-devel >> >> >> >> >
Hi, On 11-07-18 17:42, Daniel Vetter wrote: > On Wed, Jul 11, 2018 at 5:35 PM, Hans de Goede <hdegoede@redhat.com> wrote: >> Hi, >> >> On 11-07-18 17:28, Daniel Vetter wrote: >>> >>> On Wed, Jul 11, 2018 at 5:14 PM, Hans de Goede <hdegoede@redhat.com> >>> wrote: >>>> >>>> Hi, >>>> >>>> On 11-07-18 17:07, Thomas Zimmermann wrote: >>>>> >>>>> >>>>> Hi >>>>> >>>>> Am 11.07.2018 um 16:52 schrieb Steven Rostedt: >>>>>> >>>>>> >>>>>> >>>>>> What if you make lockless_register_fb visible to fbcon, and then we can >>>>>> have a macro: >>>>> >>>>> >>>>> >>>>> There are more of these macro invocations under drivers/tty/vt, which >>>>> also mess up the log during debugging. >>>> >>>> >>>> >>>> Hmm, so this option is already broken (in a way) then, my first reaction >>>> to your mail was that we should just remove that option. But that seemed >>>> a bit harsh to me so I've been working on a fix for the last 10 minutes >>>> or so. >>>> >>>> But if it is already broken I'm tempted to just remove the option and >>>> be done with it. We really need less cruft in the fbdev/fbcon code not >>>> more. >>> >>> >>> Please don't remove it, it makes debugging kms driver issues on >>> initial modeset (which is usually run from framebuffer_register, while >>> hodling the console_lock) impossible. >> >> >> OK, so if we don't remove it, we should probably make it so that it >> can be used without triggering any WARN_ONs, which would require changing >> the existing WARN_CONSOLE_UNLOCKED() so that the calls from >> drivers/tty/vt/vt.c >> also do not trigger it ? >> >> I guess one can just ignore the oopses when debugging, but debugging surely >> would be easier if there are just no oopses ? > > I'd say let's only bother with the ones in fbcon.c. Avoids the trouble > with having to expose the fb module option to vt.c somehow. The plan was actually do the things the other way around, add a flag to vt.c which when set disables the WARN_ON calls and then have fbdev[.ko] set that when the fb.lockless_fb_register option is set. > The ones > in vt.c are as old as the git history (from a quick check at least), > and in my debugging they never have been annoying (or I somehow didn't > ever hit them, not idea). There is a #if 1 #define #else #define empty around the WARN_CONSOLE_UNLOCKED() call in include/linux/console.h I've the feeling that is there as a hack to be able to quickly disable the WARN_ONs when debugging. Have you seen Steven's suggestion which he send about the same time as your mail I'm replying to here ? I personally think that doing something like that makes sense (for as long as we have the need for the lockless_fb_register debug hack). Note I've 2 patches ready to go to only fix this in fbcon.c, but I think a more thorough fix makes sense. Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Jul 11, 2018 at 7:35 PM, Hans de Goede <hdegoede@redhat.com> wrote: > Hi, > > > On 11-07-18 17:42, Daniel Vetter wrote: >> >> On Wed, Jul 11, 2018 at 5:35 PM, Hans de Goede <hdegoede@redhat.com> >> wrote: >>> >>> Hi, >>> >>> On 11-07-18 17:28, Daniel Vetter wrote: >>>> >>>> >>>> On Wed, Jul 11, 2018 at 5:14 PM, Hans de Goede <hdegoede@redhat.com> >>>> wrote: >>>>> >>>>> >>>>> Hi, >>>>> >>>>> On 11-07-18 17:07, Thomas Zimmermann wrote: >>>>>> >>>>>> >>>>>> >>>>>> Hi >>>>>> >>>>>> Am 11.07.2018 um 16:52 schrieb Steven Rostedt: >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> What if you make lockless_register_fb visible to fbcon, and then we >>>>>>> can >>>>>>> have a macro: >>>>>> >>>>>> >>>>>> >>>>>> >>>>>> There are more of these macro invocations under drivers/tty/vt, which >>>>>> also mess up the log during debugging. >>>>> >>>>> >>>>> >>>>> >>>>> Hmm, so this option is already broken (in a way) then, my first >>>>> reaction >>>>> to your mail was that we should just remove that option. But that >>>>> seemed >>>>> a bit harsh to me so I've been working on a fix for the last 10 minutes >>>>> or so. >>>>> >>>>> But if it is already broken I'm tempted to just remove the option and >>>>> be done with it. We really need less cruft in the fbdev/fbcon code not >>>>> more. >>>> >>>> >>>> >>>> Please don't remove it, it makes debugging kms driver issues on >>>> initial modeset (which is usually run from framebuffer_register, while >>>> hodling the console_lock) impossible. >>> >>> >>> >>> OK, so if we don't remove it, we should probably make it so that it >>> can be used without triggering any WARN_ONs, which would require changing >>> the existing WARN_CONSOLE_UNLOCKED() so that the calls from >>> drivers/tty/vt/vt.c >>> also do not trigger it ? >>> >>> I guess one can just ignore the oopses when debugging, but debugging >>> surely >>> would be easier if there are just no oopses ? >> >> >> I'd say let's only bother with the ones in fbcon.c. Avoids the trouble >> with having to expose the fb module option to vt.c somehow. > > > The plan was actually do the things the other way around, add a flag to > vt.c which when set disables the WARN_ON calls and then have fbdev[.ko] > set that when the fb.lockless_fb_register option is set. > >> The ones >> in vt.c are as old as the git history (from a quick check at least), >> and in my debugging they never have been annoying (or I somehow didn't >> ever hit them, not idea). > > > There is a #if 1 #define #else #define empty around the > WARN_CONSOLE_UNLOCKED() > call in include/linux/console.h I've the feeling that is there as a hack > to be able to quickly disable the WARN_ONs when debugging. > > Have you seen Steven's suggestion which he send about the same time > as your mail I'm replying to here ? I personally think that doing > something like that makes sense (for as long as we have the need > for the lockless_fb_register debug hack). > > Note I've 2 patches ready to go to only fix this in fbcon.c, but I > think a more thorough fix makes sense. Yeah Steven's suggestion looks reasonable to fix this all for good. The #if 1 predates git history, so no idea why it was added or by whom :-) -Daniel
On Wed, 11 Jul 2018 19:56:02 +0200 Daniel Vetter <daniel@ffwll.ch> wrote: > > Have you seen Steven's suggestion which he send about the same time > > as your mail I'm replying to here ? I personally think that doing > > something like that makes sense (for as long as we have the need > > for the lockless_fb_register debug hack). > > > > Note I've 2 patches ready to go to only fix this in fbcon.c, but I > > think a more thorough fix makes sense. > > Yeah Steven's suggestion looks reasonable to fix this all for good. > The #if 1 predates git history, so no idea why it was added or by whom > :-) I just sent the patch. If the printk maintainers take it, then you can update the fb driver to set the ignore_console_lock_warning when lockless_fb_register is set. -- Steve -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, On 11-07-18 21:19, Steven Rostedt wrote: > On Wed, 11 Jul 2018 19:56:02 +0200 > Daniel Vetter <daniel@ffwll.ch> wrote: > >>> Have you seen Steven's suggestion which he send about the same time >>> as your mail I'm replying to here ? I personally think that doing >>> something like that makes sense (for as long as we have the need >>> for the lockless_fb_register debug hack). >>> >>> Note I've 2 patches ready to go to only fix this in fbcon.c, but I >>> think a more thorough fix makes sense. >> >> Yeah Steven's suggestion looks reasonable to fix this all for good. >> The #if 1 predates git history, so no idea why it was added or by whom >> :-) > > I just sent the patch. If the printk maintainers take it, then you can > update the fb driver to set the ignore_console_lock_warning when > lockless_fb_register is set. Thanks for doing this. I will wait with sending a fbcon / fbdev patch till the fate of your patch is clear then. Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi, On (07/11/18 16:46), Thomas Zimmermann wrote: > 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. Hmm. I once dealt with WARN_CONSOLE_UNLOCKED(), and back then, IIRC, I really wanted to turn it into WARN_ONCE_CONSOLE_UNLOCKED(), which would WARN_ON_ONCE() instead of WARN_ON(). It's just a bit too noisy and verbose and a single backtrace was already enough. -ss -- To unsubscribe from this list: send the line "unsubscribe linux-fbdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am 11.07.2018 um 21:19 schrieb Steven Rostedt: > I just sent the patch. If the printk maintainers take it, then you can > update the fb driver to set the ignore_console_lock_warning when > lockless_fb_register is set. Thank you. > > -- Steve > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel >
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);