[PATCH 08/10] dma: imx-sdma: abort updating channel when it has been terminated

[Jiada Wang]

In case the corresponding channel has already been terminated,
then instead of go on updating channel status, driver should abort from
sdma_handle_channel_loop(), otherwise channel status will be updated
incorrecly.

This patch also adds lock to avoid race between terminate of channel,
and updaing of channel status in sdma_handle_channel_loop().

Signed-off-by: Jiada Wang <jiada_w...@mentor.com>
---
 drivers/dma/imx-sdma.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 0b23407..bc867e5 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -664,16 +664,25 @@ static void sdma_event_disable(struct sdma_channel 
*sdmac, unsigned int event)
 static void sdma_handle_channel_loop(struct sdma_channel *sdmac)
 {
        struct sdma_buffer_descriptor *bd;
+       unsigned long flags;
 
        /*
         * loop mode. Iterate over descriptors, re-setup them and
         * call callback function.
         */
        while (1) {
+               spin_lock_irqsave(&sdmac->lock, flags);
+               if (!sdmac->enabled) {
+                       spin_unlock_irqrestore(&sdmac->lock, flags);
+                       break;
+               }
+
                bd = &sdmac->bd[sdmac->buf_tail];
 
-               if (bd->mode.status & BD_DONE)
+               if (bd->mode.status & BD_DONE) {
+                       spin_unlock_irqrestore(&sdmac->lock, flags);
                        break;
+               }
 
                if (bd->mode.status & BD_RROR)
                        sdmac->status = DMA_ERROR;
@@ -690,6 +699,7 @@ static void sdma_handle_channel_loop(struct sdma_channel 
*sdmac)
                        bd->mode.count = sdmac->chn_count;
                }
 
+               spin_unlock_irqrestore(&sdmac->lock, flags);
                if (sdmac->desc.callback)
                        sdmac->desc.callback(sdmac->desc.callback_param);
        }
-- 
2.4.5