[Intel-gfx] [PATCH] drm/crc-debugfs: User irqsafe spinlock in drm_crtc_add_crc_entry

[Benjamin Gaignard]

Le jeu. 6 juin 2019 à 10:12, Ville Syrjälä
<ville.syrjala at linux.intel.com> a écrit :
>
> On Wed, Jun 05, 2019 at 09:45:56PM +0200, Daniel Vetter wrote:
> > We can be called from any context, we need to be prepared.
> >
> > Noticed this while hacking on vkms, which calls this function from a
> > normal worker. Which really upsets lockdep.
> >
> > Cc: Rodrigo Siqueira <rodrigosiqueiramelo at gmail.com>
> > Cc: Tomeu Vizoso <tomeu.vizoso at collabora.com>
> > Cc: Emil Velikov <emil.velikov at collabora.com>
> > Cc: Benjamin Gaignard <benjamin.gaignard at linaro.org>
> > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
>
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Reviewed-by: Benjamin Gaignard <benjamin.gaignard at linaro.org>

>
> > ---
> >  drivers/gpu/drm/drm_debugfs_crc.c | 5 +++--
> >  1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_debugfs_crc.c b/drivers/gpu/drm/drm_debugfs_crc.c
> > index 585169f0dcc5..7f35b5ba1924 100644
> > --- a/drivers/gpu/drm/drm_debugfs_crc.c
> > +++ b/drivers/gpu/drm/drm_debugfs_crc.c
> > @@ -396,8 +396,9 @@ int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
> >       struct drm_crtc_crc *crc = &crtc->crc;
> >       struct drm_crtc_crc_entry *entry;
> >       int head, tail;
> > +     unsigned long flags;
> >
> > -     spin_lock(&crc->lock);
> > +     spin_lock_irqsave(&crc->lock, flags);
> >
> >       /* Caller may not have noticed yet that userspace has stopped reading */
> >       if (!crc->entries) {
> > @@ -428,7 +429,7 @@ int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
> >       head = (head + 1) & (DRM_CRC_ENTRIES_NR - 1);
> >       crc->head = head;
> >
> > -     spin_unlock(&crc->lock);
> > +     spin_unlock_irqrestore(&crc->lock, flags);
> >
> >       wake_up_interruptible(&crc->wq);
> >
> > --
> > 2.20.1
> >
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
>
> --
> Ville Syrjälä
> Intel
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel