media: stm32: dcmi: rework spin_lock calls

Rework of the spin_lock calls in preparation of the rework
of the data handling of the driver. Keep it straight forward
with basically spin_lock protection around everything except
dmaengine calls that might sleep (ex: synchronize / terminate)

Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

diff --git a/drivers/media/platform/st/stm32/stm32-dcmi.c b/drivers/media/platform/st/stm32/stm32-dcmi.c
index 20f5b9ab6a1c664710912f5a9f27032e0aef2c65..2fec10d13913a056561d7f40caed0b766065b110 100644 (file)
--- a/drivers/media/platform/st/stm32/stm32-dcmi.c
+++ b/drivers/media/platform/st/stm32/stm32-dcmi.c
@@ -227,25 +227,18 @@ static int dcmi_restart_capture(struct stm32_dcmi *dcmi)
 {
        struct dcmi_buf *buf;
 
-       spin_lock_irq(&dcmi->irqlock);
-
-       if (dcmi->state != RUNNING) {
-               spin_unlock_irq(&dcmi->irqlock);
+       if (dcmi->state != RUNNING)
                return -EINVAL;
-       }
 
        /* Restart a new DMA transfer with next buffer */
        if (list_empty(&dcmi->buffers)) {
                dev_dbg(dcmi->dev, "Capture restart is deferred to next buffer queueing\n");
                dcmi->state = WAIT_FOR_BUFFER;
-               spin_unlock_irq(&dcmi->irqlock);
                return 0;
        }
        buf = list_entry(dcmi->buffers.next, struct dcmi_buf, list);
        dcmi->active = buf;
 
-       spin_unlock_irq(&dcmi->irqlock);
-
        return dcmi_start_capture(dcmi, buf);
 }
 
@@ -370,8 +363,10 @@ static void dcmi_process_jpeg(struct stm32_dcmi *dcmi)
         * buffer payload.
         */
 
+       spin_unlock_irq(&dcmi->irqlock);
        /* Drain DMA */
        dmaengine_synchronize(dcmi->dma_chan);
+       spin_lock_irq(&dcmi->irqlock);
 
        /* Get DMA residue to get JPEG size */
        status = dmaengine_tx_status(dcmi->dma_chan, dcmi->dma_cookie, &state);
@@ -386,8 +381,10 @@ static void dcmi_process_jpeg(struct stm32_dcmi *dcmi)
                dcmi_buffer_done(dcmi, buf, 0, -EIO);
        }
 
+       spin_unlock_irq(&dcmi->irqlock);
        /* Abort DMA operation */
        dmaengine_terminate_sync(dcmi->dma_chan);
+       spin_lock_irq(&dcmi->irqlock);
 
        /* Restart capture */
        if (dcmi_restart_capture(dcmi))
@@ -413,8 +410,10 @@ static irqreturn_t dcmi_irq_thread(int irq, void *arg)
                spin_unlock_irq(&dcmi->irqlock);
                dmaengine_terminate_sync(dcmi->dma_chan);
 
+               spin_lock_irq(&dcmi->irqlock);
                if (dcmi_restart_capture(dcmi))
                        dev_err(dcmi->dev, "%s: Cannot restart capture\n", __func__);
+               spin_unlock_irq(&dcmi->irqlock);
 
                return IRQ_HANDLED;
        }
@@ -424,8 +423,8 @@ static irqreturn_t dcmi_irq_thread(int irq, void *arg)
        if (dcmi->sd_format->fourcc == V4L2_PIX_FMT_JPEG &&
            dcmi->misr & IT_FRAME) {
                /* JPEG received */
-               spin_unlock_irq(&dcmi->irqlock);
                dcmi_process_jpeg(dcmi);
+               spin_unlock_irq(&dcmi->irqlock);
                return IRQ_HANDLED;
        }
 
@@ -599,11 +598,9 @@ 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);
 
-               spin_unlock_irq(&dcmi->irqlock);
                if (dcmi_start_capture(dcmi, buf))
                        dev_err(dcmi->dev, "%s: Cannot restart capture on overflow or error\n",
                                __func__);
-               return;
        }
 
        spin_unlock_irq(&dcmi->irqlock);
@@ -812,11 +809,11 @@ 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, buf);
        if (ret) {
                dev_err(dcmi->dev, "%s: Start streaming failed, cannot start capture\n",
                        __func__);
+               spin_unlock_irq(&dcmi->irqlock);
                goto err_pipeline_stop;
        }
 
@@ -826,6 +823,8 @@ static int dcmi_start_streaming(struct vb2_queue *vq, unsigned int count)
        else
                reg_set(dcmi->regs, DCMI_IER, IT_OVR | IT_ERR);
 
+       spin_unlock_irq(&dcmi->irqlock);
+
        return 0;
 
 err_pipeline_stop: