1 files changed, 20 insertions, 5 deletions

diff --git a/drivers/media/video/pxa_camera.c b/drivers/media/video/pxa_camera.c
index a2f98ec14d9a..cfa113cedd3e 100644
--- a/drivers/media/video/pxa_camera.c
+++ b/drivers/media/video/pxa_camera.c
@@ -624,6 +624,7 @@ static void pxa_camera_stop_capture(struct pxa_camera_dev *pcdev)
         cicr0 = __raw_readl(pcdev->base + CICR0) & ~CICR0_ENB;
         __raw_writel(cicr0, pcdev->base + CICR0);
 
+        pcdev->active = NULL;
         dev_dbg(pcdev->dev, "%s\n", __func__);
 }
 
@@ -697,7 +698,6 @@ static void pxa_camera_wakeup(struct pxa_camera_dev *pcdev,
 
         if (list_empty(&pcdev->capture)) {
                 pxa_camera_stop_capture(pcdev);
-                pcdev->active = NULL;
                 for (i = 0; i < pcdev->channels; i++)
                         pcdev->sg_tail[i] = NULL;
                 return;
@@ -765,10 +765,20 @@ static void pxa_camera_dma_irq(int channel, struct pxa_camera_dev *pcdev,
                 goto out;
         }
 
-        if (!pcdev->active) {
-                dev_err(pcdev->dev, "DMA End IRQ with no active buffer!\n");
+        /*
+         * pcdev->active should not be NULL in DMA irq handler.
+         *
+         * But there is one corner case : if capture was stopped due to an
+         * overrun of channel 1, and at that same channel 2 was completed.
+         *
+         * When handling the overrun in DMA irq for channel 1, we'll stop the
+         * capture and restart it (and thus set pcdev->active to NULL). But the
+         * DMA irq handler will already be pending for channel 2. So on entering
+         * the DMA irq handler for channel 2 there will be no active buffer, yet
+         * that is normal.
+         */
+        if (!pcdev->active)
                 goto out;
-        }
 
         vb = &pcdev->active->vb;
         buf = container_of(vb, struct pxa_buffer, vb);
@@ -779,7 +789,12 @@ static void pxa_camera_dma_irq(int channel, struct pxa_camera_dev *pcdev,
                 status & DCSR_ENDINTR ? "EOF " : "", vb, DDADR(channel));
 
         if (status & DCSR_ENDINTR) {
-                if (camera_status & overrun) {
+                /*
+                 * It's normal if the last frame creates an overrun, as there
+                 * are no more DMA descriptors to fetch from QCI fifos
+                 */
+                if (camera_status & overrun &&
+                    !list_is_last(pcdev->capture.next, &pcdev->capture)) {
                         dev_dbg(pcdev->dev, "FIFO overrun! CISR: %x\n",
                                 camera_status);
                         pxa_camera_stop_capture(pcdev);