Hi,
On Monday 14 April 2014 06:06 PM, Tomi Valkeinen wrote:
> On 11/04/14 10:23, Archit Taneja wrote:
>> The vblank_cb callback and the page_flip ioctl can occur together in
>> different
>> CPU contexts. vblank_cb uses takes tje drm device's event_lock spinlock when
>> sending the vblank event and updating omap_crtc->event and omap_crtc->od_fb.
>>
>> Use the same spinlock in page_flip, to make sure the above omap_crtc
>> parameters
>> are configured sequentially.
>>
>> Signed-off-by: Archit Taneja <archit at ti.com>
>> ---
>> drivers/gpu/drm/omapdrm/omap_crtc.c | 4 ++++
>> 1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/omapdrm/omap_crtc.c
>> b/drivers/gpu/drm/omapdrm/omap_crtc.c
>> index d74c72c..9c7af42 100644
>> --- a/drivers/gpu/drm/omapdrm/omap_crtc.c
>> +++ b/drivers/gpu/drm/omapdrm/omap_crtc.c
>> @@ -350,6 +350,7 @@ static int omap_crtc_page_flip_locked(struct drm_crtc
>> *crtc,
>> struct drm_device *dev = crtc->dev;
>> struct omap_crtc *omap_crtc = to_omap_crtc(crtc);
>> struct drm_gem_object *bo;
>> + unsigned long flags;
>>
>> DBG("%d -> %d (event=%p)", crtc->fb ? crtc->fb->base.id : -1,
>> fb->base.id, event);
>> @@ -359,9 +360,12 @@ static int omap_crtc_page_flip_locked(struct drm_crtc
>> *crtc,
>> return -EINVAL;
>> }
>>
>> + spin_lock_irqsave(&dev->event_lock, flags);
>> +
>> omap_crtc->event = event;
>> omap_crtc->old_fb = crtc->fb = fb;
>>
>> + spin_unlock_irqrestore(&dev->event_lock, flags);
>
> There's
>
> if (omap_crtc->old_fb)
>
> just above the code you changed. Shouldn't that also be inside the spinlock?
Yes, that should come within the spinlock too.
On a related note, the mdp5_crtc->event in mdp5_crtc_page_flip(and for
mdp4 crtc) should also be inside the spinlock.
>
> Also, the description contains a few typos.
I'll fix these.
Thanks,
Archit
