Hi,
On Wednesday 10 August 2011 16:03:26 Deepthy Ravi wrote:
> From: Abhilash K V <abhilash...@ti.com>
>
> This patch fixes the kernel crash introduced by the previous
> patch:
> omap3: ISP: Fix the failure of CCDC capture during
> suspend/resume.
> This null pointer exception happens when attempting suspend
> while the ISP driver is not being used. The current patch
> fixes this by deferring the code (as introduced in the
> aforementioned patch) to handle buffer-starvation to get
> called only if the ISP reference count is non-zero.
> An additional safety check is also added to ensure that
> buffer-starvation logic kicks in for an empty dmaqueue only
> if the ISP pipeline is not in the stopped state.
What about squashing this with the previous patch then ?
I'll review patch 1/2, just give me a bit more time. The race condition is
tricky so I need to rest a bit before attacking it :-)
> Signed-off-by: Abhilash K V <abhilash...@ti.com>
> Signed-off-by: Deepthy Ravi <deepthy.r...@ti.com>
> ---
> drivers/media/video/omap3isp/isp.c | 12 ++++++------
> drivers/media/video/omap3isp/ispvideo.c | 4 +++-
> 2 files changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/media/video/omap3isp/isp.c
> b/drivers/media/video/omap3isp/isp.c index 6604fbd..6acdedc 100644
> --- a/drivers/media/video/omap3isp/isp.c
> +++ b/drivers/media/video/omap3isp/isp.c
> @@ -1573,6 +1573,9 @@ static int isp_pm_prepare(struct device *dev)
> unsigned long flags;
>
> WARN_ON(mutex_is_locked(&isp->isp_mutex));
> + if (isp->ref_count == 0)
> + return 0;
> +
> spin_lock_irqsave(&pipe->lock, flags);
> pipe->state |= ISP_PIPELINE_PREPARE_SUSPEND;
> spin_unlock_irqrestore(&pipe->lock, flags);
> @@ -1581,9 +1584,6 @@ static int isp_pm_prepare(struct device *dev)
> if (err < 0)
> return err;
>
> - if (isp->ref_count == 0)
> - return 0;
> -
> reset = isp_suspend_modules(isp);
> isp_disable_interrupts(isp);
> isp_save_ctx(isp);
> @@ -1613,13 +1613,13 @@ static int isp_pm_resume(struct device *dev)
> struct isp_pipeline *pipe = to_isp_pipeline(&video->video.entity);
> unsigned long flags;
>
> + if (isp->ref_count == 0)
> + return 0;
> +
> spin_lock_irqsave(&pipe->lock, flags);
> pipe->state &= ~ISP_PIPELINE_PREPARE_SUSPEND;
> spin_unlock_irqrestore(&pipe->lock, flags);
>
> - if (isp->ref_count == 0)
> - return 0;
> -
> return isp_enable_clocks(isp);
> }
>
> diff --git a/drivers/media/video/omap3isp/ispvideo.c
> b/drivers/media/video/omap3isp/ispvideo.c index bf149a7..ffb339c 100644
> --- a/drivers/media/video/omap3isp/ispvideo.c
> +++ b/drivers/media/video/omap3isp/ispvideo.c
> @@ -726,8 +726,10 @@ int isp_video_handle_buffer_starvation(struct
> isp_video *video) struct isp_video_queue *queue = video->queue;
> struct isp_video_buffer *buf;
> struct list_head *head = &video->dmaqueue;
> + struct isp_ccdc_device *ccdc = &video->isp->isp_ccdc;
>
> - if (list_empty(&video->dmaqueue)) {
> + if (list_empty(&video->dmaqueue)
> + && ccdc->state != ISP_PIPELINE_STREAM_STOPPED) {
> err = isp_video_deq_enq(queue);
> } else if (head->next->next == head) {
> /* only one buffer is left on dmaqueue */
--
Regards,
Laurent Pinchart
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