[PATCH v5 3/5] [media] davinci: vpif_capture: fix start/stop streaming locking
From: laurent.pinchart@ideasonboard.com (Laurent Pinchart)
Date: 2016-12-07 14:47:11
Also in:
linux-media
Hi Kevin, Thank you for the patch. On Tuesday 06 Dec 2016 21:08:24 Kevin Hilman wrote:
Video capture subdevs may be over I2C and may sleep during xfer, so we cannot do IRQ-disabled locking when calling the subdev. The IRQ-disabled locking is meant to protect the DMA queue list throughout the rest of the driver, so update the locking in [start|stop]_streaming to protect just this list. Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Kevin Hilman <khilman@baylibre.com>
I would also add a comment to document the irqlock field as protecting the dma_queue list only. Something like - /* Used in video-buf */ + /* Protects the dma_queue field */ spinlock_t irqlock; With that, Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
quoted hunk ↗ jump to hunk
--- drivers/media/platform/davinci/vpif_capture.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)diff --git a/drivers/media/platform/davinci/vpif_capture.cb/drivers/media/platform/davinci/vpif_capture.c index c24049acd40a..f72a719efb3d 100644--- a/drivers/media/platform/davinci/vpif_capture.c +++ b/drivers/media/platform/davinci/vpif_capture.c@@ -179,8 +179,6 @@ static int vpif_start_streaming(struct vb2_queue *vq,unsigned int count) unsigned long addr, flags; int ret; - spin_lock_irqsave(&common->irqlock, flags); - /* Initialize field_id */ ch->field_id = 0;@@ -211,6 +209,7 @@ static int vpif_start_streaming(struct vb2_queue *vq,unsigned int count) vpif_config_addr(ch, ret); /* Get the next frame from the buffer queue */ + spin_lock_irqsave(&common->irqlock, flags); common->cur_frm = common->next_frm = list_entry(common- dma_queue.next, struct vpif_cap_buffer, list); /* Remove buffer from the buffer queue */@@ -244,6 +243,7 @@ static int vpif_start_streaming(struct vb2_queue *vq,unsigned int count) return 0; err: + spin_lock_irqsave(&common->irqlock, flags); list_for_each_entry_safe(buf, tmp, &common->dma_queue, list) { list_del(&buf->list); vb2_buffer_done(&buf->vb.vb2_buf, VB2_BUF_STATE_QUEUED);@@ -287,7 +287,6 @@ static void vpif_stop_streaming(struct vb2_queue *vq) vpif_dbg(1, debug, "stream off failed in subdev\n"); /* release all active buffers */ - spin_lock_irqsave(&common->irqlock, flags); if (common->cur_frm == common->next_frm) { vb2_buffer_done(&common->cur_frm->vb.vb2_buf, VB2_BUF_STATE_ERROR);@@ -300,6 +299,7 @@ static void vpif_stop_streaming(struct vb2_queue *vq) VB2_BUF_STATE_ERROR); } + 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);
-- Regards, Laurent Pinchart