| Message ID | 20240528112901.476068-3-luciano.coelho@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915: prevent some static analyzer warnings | expand |
On Tue, May 28, 2024 at 02:29:01PM +0300, Luca Coelho wrote: > In intel_crtc_vblank_work(), we access uapi.event before grabbing the > event_lock spinlock, but modify it inside the spinlock block. This > causes some static analyzers to get confused and issue a warning. > > The uapi.event value is not protected by the event_lock, so we can > safely move it out of the protected block to prevent false positives. My first reaction was to think about moving the lock before the if, but then I went down to see the event_lock definition and usage in drm and see some other precedences on this and agree this is safe and better. Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com> > > Signed-off-by: Luca Coelho <luciano.coelho@intel.com> > --- > drivers/gpu/drm/i915/display/intel_crtc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c > index ca6dc1dc56c8..bf6e74e99f5c 100644 > --- a/drivers/gpu/drm/i915/display/intel_crtc.c > +++ b/drivers/gpu/drm/i915/display/intel_crtc.c > @@ -411,8 +411,8 @@ static void intel_crtc_vblank_work(struct kthread_work *base) > if (crtc_state->uapi.event) { > spin_lock_irq(&crtc->base.dev->event_lock); > drm_crtc_send_vblank_event(&crtc->base, crtc_state->uapi.event); > - crtc_state->uapi.event = NULL; > spin_unlock_irq(&crtc->base.dev->event_lock); > + crtc_state->uapi.event = NULL; > } > > trace_intel_crtc_vblank_work_end(crtc); > -- > 2.39.2 >
diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c index ca6dc1dc56c8..bf6e74e99f5c 100644 --- a/drivers/gpu/drm/i915/display/intel_crtc.c +++ b/drivers/gpu/drm/i915/display/intel_crtc.c @@ -411,8 +411,8 @@ static void intel_crtc_vblank_work(struct kthread_work *base) if (crtc_state->uapi.event) { spin_lock_irq(&crtc->base.dev->event_lock); drm_crtc_send_vblank_event(&crtc->base, crtc_state->uapi.event); - crtc_state->uapi.event = NULL; spin_unlock_irq(&crtc->base.dev->event_lock); + crtc_state->uapi.event = NULL; } trace_intel_crtc_vblank_work_end(crtc);
In intel_crtc_vblank_work(), we access uapi.event before grabbing the event_lock spinlock, but modify it inside the spinlock block. This causes some static analyzers to get confused and issue a warning. The uapi.event value is not protected by the event_lock, so we can safely move it out of the protected block to prevent false positives. Signed-off-by: Luca Coelho <luciano.coelho@intel.com> --- drivers/gpu/drm/i915/display/intel_crtc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)