media: stm32-dcmi: fix lock scheme

Fix lock scheme leading to spurious freeze.

Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
index cc104a0805e29f01ba8820daf6eb7e7034c868ac..37d82d3e33f9b1148ee0a930c8d6442a2fccb388 100644 (file)
--- a/drivers/media/platform/stm32/stm32-dcmi.c
+++ b/drivers/media/platform/stm32/stm32-dcmi.c
@@ -197,7 +197,7 @@ static void dcmi_dma_callback(void *param)
        struct dma_tx_state state;
        enum dma_status status;
 
-       spin_lock(&dcmi->irqlock);
+       spin_lock_irq(&dcmi->irqlock);
 
        /* Check DMA status */
        status = dmaengine_tx_status(chan, dcmi->dma_cookie, &state);
@@ -239,7 +239,7 @@ static void dcmi_dma_callback(void *param)
                                dcmi->errors_count++;
                                dcmi->active = NULL;
 
-                               spin_unlock(&dcmi->irqlock);
+                               spin_unlock_irq(&dcmi->irqlock);
                                return;
                        }
 
@@ -248,13 +248,11 @@ static void dcmi_dma_callback(void *param)
 
                        list_del_init(&dcmi->active->list);
 
-                       if (dcmi_start_capture(dcmi)) {
+                       spin_unlock_irq(&dcmi->irqlock);
+                       if (dcmi_start_capture(dcmi))
                                dev_err(dcmi->dev, "%s: Cannot restart capture on DMA complete\n",
                                        __func__);
-
-                               spin_unlock(&dcmi->irqlock);
-                               return;
-                       }
+                       return;
                }
 
                break;
@@ -263,7 +261,7 @@ static void dcmi_dma_callback(void *param)
                break;
        }
 
-       spin_unlock(&dcmi->irqlock);
+       spin_unlock_irq(&dcmi->irqlock);
 }
 
 static int dcmi_start_dma(struct stm32_dcmi *dcmi,
@@ -360,7 +358,7 @@ static irqreturn_t dcmi_irq_thread(int irq, void *arg)
 {
        struct stm32_dcmi *dcmi = arg;
 
-       spin_lock(&dcmi->irqlock);
+       spin_lock_irq(&dcmi->irqlock);
 
        /* Stop capture is required */
        if (dcmi->state == STOPPING) {
@@ -370,7 +368,7 @@ static irqreturn_t dcmi_irq_thread(int irq, void *arg)
 
                complete(&dcmi->complete);
 
-               spin_unlock(&dcmi->irqlock);
+               spin_unlock_irq(&dcmi->irqlock);
                return IRQ_HANDLED;
        }
 
@@ -383,35 +381,34 @@ static irqreturn_t dcmi_irq_thread(int irq, void *arg)
                         __func__);
 
                dcmi->errors_count++;
-               dmaengine_terminate_all(dcmi->dma_chan);
-
                dev_dbg(dcmi->dev, "Restarting capture after DCMI error\n");
 
-               if (dcmi_start_capture(dcmi)) {
+               spin_unlock_irq(&dcmi->irqlock);
+               dmaengine_terminate_all(dcmi->dma_chan);
+
+               if (dcmi_start_capture(dcmi))
                        dev_err(dcmi->dev, "%s: Cannot restart capture on overflow or error\n",
                                __func__);
-
-                       spin_unlock(&dcmi->irqlock);
-                       return IRQ_HANDLED;
-               }
+               return IRQ_HANDLED;
        }
 
-       spin_unlock(&dcmi->irqlock);
+       spin_unlock_irq(&dcmi->irqlock);
        return IRQ_HANDLED;
 }
 
 static irqreturn_t dcmi_irq_callback(int irq, void *arg)
 {
        struct stm32_dcmi *dcmi = arg;
+       unsigned long flags;
 
-       spin_lock(&dcmi->irqlock);
+       spin_lock_irqsave(&dcmi->irqlock, flags);
 
        dcmi->misr = reg_read(dcmi->regs, DCMI_MIS);
 
        /* Clear interrupt */
        reg_set(dcmi->regs, DCMI_ICR, IT_FRAME | IT_OVR | IT_ERR);
 
-       spin_unlock(&dcmi->irqlock);
+       spin_unlock_irqrestore(&dcmi->irqlock, flags);
 
        return IRQ_WAKE_THREAD;
 }
@@ -490,9 +487,8 @@ static void dcmi_buf_queue(struct vb2_buffer *vb)
        struct stm32_dcmi *dcmi =  vb2_get_drv_priv(vb->vb2_queue);
        struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
        struct dcmi_buf *buf = container_of(vbuf, struct dcmi_buf, vb);
-       unsigned long flags = 0;
 
-       spin_lock_irqsave(&dcmi->irqlock, flags);
+       spin_lock_irq(&dcmi->irqlock);
 
        if ((dcmi->state == RUNNING) && (!dcmi->active)) {
                dcmi->active = buf;
@@ -500,19 +496,15 @@ static void dcmi_buf_queue(struct vb2_buffer *vb)
                dev_dbg(dcmi->dev, "Starting capture on buffer[%d] queued\n",
                        buf->vb.vb2_buf.index);
 
-               if (dcmi_start_capture(dcmi)) {
+               spin_unlock_irq(&dcmi->irqlock);
+               if (dcmi_start_capture(dcmi))
                        dev_err(dcmi->dev, "%s: Cannot restart capture on overflow or error\n",
                                __func__);
-
-                       spin_unlock_irqrestore(&dcmi->irqlock, flags);
-                       return;
-               }
        } else {
                /* Enqueue to video buffers list */
                list_add_tail(&buf->list, &dcmi->buffers);
+               spin_unlock_irq(&dcmi->irqlock);
        }
-
-       spin_unlock_irqrestore(&dcmi->irqlock, flags);
 }
 
 static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
@@ -598,20 +590,17 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
 
        dev_dbg(dcmi->dev, "Start streaming, starting capture\n");
 
+       spin_unlock_irq(&dcmi->irqlock);
        ret = dcmi_start_capture(dcmi);
        if (ret) {
                dev_err(dcmi->dev, "%s: Start streaming failed, cannot start capture\n",
                        __func__);
-
-               spin_unlock_irq(&dcmi->irqlock);
                goto err_subdev_streamoff;
        }
 
        /* Enable interruptions */
        reg_set(dcmi->regs, DCMI_IER, IT_FRAME | IT_OVR | IT_ERR);
 
-       spin_unlock_irq(&dcmi->irqlock);
-
        return 0;
 
 err_subdev_streamoff:
@@ -654,7 +643,9 @@ static void dcmi_stop_streaming(struct vb2_queue *vq)
                dev_err(dcmi->dev, "%s: Failed to stop streaming, subdev streamoff error (%d)\n",
                        __func__, ret);
 
+       spin_lock_irq(&dcmi->irqlock);
        dcmi->state = STOPPING;
+       spin_unlock_irq(&dcmi->irqlock);
 
        timeout = wait_for_completion_interruptible_timeout(&dcmi->complete,
                                                            time_ms);