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[media] vpif_capture: protect dma_queue by a spin_lock

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The dma_queue list is accessed by both the interrupt handler and by normal
code. It needs to be protected by a lock to prevent possible list corruption.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Lad, Prabhakar <prabhakar.lad@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Hans Verkuil 2012-11-16 12:03:06 -03:00 committed by Mauro Carvalho Chehab
parent 94b76a88f1
commit aec968326d
1 changed files with 23 additions and 3 deletions
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26
drivers/media/platform/davinci/vpif_capture.c
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@ -201,13 +201,16 @@ static void vpif_buffer_queue(struct vb2_buffer *vb)
struct vpif_cap_buffer *buf = container_of(vb,
struct vpif_cap_buffer, vb);
struct common_obj *common;
unsigned long flags;
common = &ch->common[VPIF_VIDEO_INDEX];
vpif_dbg(2, debug, "vpif_buffer_queue\n");
spin_lock_irqsave(&common->irqlock, flags);
/* add the buffer to the DMA queue */
list_add_tail(&buf->list, &common->dma_queue);
spin_unlock_irqrestore(&common->irqlock, flags);
}
/**
@ -278,10 +281,13 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count)
struct common_obj *common = &ch->common[VPIF_VIDEO_INDEX];
struct vpif_params *vpif = &ch->vpifparams;
unsigned long addr = 0;
unsigned long flags;
int ret;
/* If buffer queue is empty, return error */
/* If buffer queue is empty, return error */
spin_lock_irqsave(&common->irqlock, flags);
if (list_empty(&common->dma_queue)) {
spin_unlock_irqrestore(&common->irqlock, flags);
vpif_dbg(1, debug, "buffer queue is empty\n");
return -EIO;
}
@ -291,6 +297,7 @@ static int vpif_start_streaming(struct vb2_queue *vq, unsigned int count)
struct vpif_cap_buffer, list);
/* Remove buffer from the buffer queue */
list_del(&common->cur_frm->list);
spin_unlock_irqrestore(&common->irqlock, flags);
/* Mark state of the current frame to active */
common->cur_frm->vb.state = VB2_BUF_STATE_ACTIVE;
/* Initialize field_id and started member */
@ -362,6 +369,7 @@ static int vpif_stop_streaming(struct vb2_queue *vq)
struct vpif_fh *fh = vb2_get_drv_priv(vq);
struct channel_obj *ch = fh->channel;
struct common_obj *common;
unsigned long flags;
if (!vb2_is_streaming(vq))
return 0;
@ -369,12 +377,14 @@ static int vpif_stop_streaming(struct vb2_queue *vq)
common = &ch->common[VPIF_VIDEO_INDEX];
/* release all active buffers */
spin_lock_irqsave(&common->irqlock, flags);
while (!list_empty(&common->dma_queue)) {
common->next_frm = list_entry(common->dma_queue.next,
struct vpif_cap_buffer, list);
list_del(&common->next_frm->list);
vb2_buffer_done(&common->next_frm->vb, VB2_BUF_STATE_ERROR);
}
spin_unlock_irqrestore(&common->irqlock, flags);
return 0;
}
@ -420,10 +430,12 @@ static void vpif_schedule_next_buffer(struct common_obj *common)
{
unsigned long addr = 0;
spin_lock(&common->irqlock);
common->next_frm = list_entry(common->dma_queue.next,
struct vpif_cap_buffer, list);
/* Remove that buffer from the buffer queue */
list_del(&common->next_frm->list);
spin_unlock(&common->irqlock);
common->next_frm->vb.state = VB2_BUF_STATE_ACTIVE;
addr = vb2_dma_contig_plane_dma_addr(&common->next_frm->vb, 0);
@ -468,8 +480,12 @@ static irqreturn_t vpif_channel_isr(int irq, void *dev_id)
/* Check the field format */
if (1 == ch->vpifparams.std_info.frm_fmt) {
/* Progressive mode */
if (list_empty(&common->dma_queue))
spin_lock(&common->irqlock);
if (list_empty(&common->dma_queue)) {
spin_unlock(&common->irqlock);
continue;
}
spin_unlock(&common->irqlock);
if (!channel_first_int[i][channel_id])
vpif_process_buffer_complete(common);
@ -513,9 +529,13 @@ static irqreturn_t vpif_channel_isr(int irq, void *dev_id)
vpif_process_buffer_complete(common);
} else if (1 == fid) {
/* odd field */
spin_lock(&common->irqlock);
if (list_empty(&common->dma_queue) ||
(common->cur_frm != common->next_frm))
(common->cur_frm != common->next_frm)) {
spin_unlock(&common->irqlock);
continue;
}
spin_unlock(&common->irqlock);
vpif_schedule_next_buffer(common);
}