dmaengine: fsl-edma: change to guard(mutex) within fsl_edma3_xlate()

Introduce a scope guard to automatically unlock the mutex within
fsl_edma3_xlate() to simplify the code.

Prepare to add source ID checks in the future.

Signed-off-by: Joy Zou <joy.zou@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20240701070232.2519179-2-joy.zou@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/fsl-edma-main.c b/drivers/dma/fsl-edma-main.c
index c66185c5a199257b8baee0d76a7d0a2b9d11ed1d..d4f29ece69f549fe4688df9e0fff11bf789c62c0 100644 (file)
--- a/drivers/dma/fsl-edma-main.c
+++ b/drivers/dma/fsl-edma-main.c
@@ -153,7 +153,7 @@ static struct dma_chan *fsl_edma3_xlate(struct of_phandle_args *dma_spec,
 
        b_chmux = !!(fsl_edma->drvdata->flags & FSL_EDMA_DRV_HAS_CHMUX);
 
-       mutex_lock(&fsl_edma->fsl_edma_mutex);
+       guard(mutex)(&fsl_edma->fsl_edma_mutex);
        list_for_each_entry_safe(chan, _chan, &fsl_edma->dma_dev.channels,
                                        device_node) {
 
@@ -177,18 +177,15 @@ static struct dma_chan *fsl_edma3_xlate(struct of_phandle_args *dma_spec,
                if (!b_chmux && i == dma_spec->args[0]) {
                        chan = dma_get_slave_channel(chan);
                        chan->device->privatecnt++;
-                       mutex_unlock(&fsl_edma->fsl_edma_mutex);
                        return chan;
                } else if (b_chmux && !fsl_chan->srcid) {
                        /* if controller support channel mux, choose a free channel */
                        chan = dma_get_slave_channel(chan);
                        chan->device->privatecnt++;
                        fsl_chan->srcid = dma_spec->args[0];
-                       mutex_unlock(&fsl_edma->fsl_edma_mutex);
                        return chan;
                }
        }
-       mutex_unlock(&fsl_edma->fsl_edma_mutex);
        return NULL;
 }