[PATCH v2] mmc: bcm2835: Use dma_request_chan() instead dma_request_slave_channel()

Peter Ujfalusi
2019-12-17T12:22:55Z

dma_request_slave_channel() is a wrapper on top of dma_request_chan()
eating up the error code.

By using dma_request_chan() directly the driver can support deferred
probing against DMA.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
Hi,

Changes since v1:
- instead of returning jump to err: to free up resources

Regards,
Peter

drivers/mmc/host/bcm2835.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
index 99f61fd2a658..c3d949847cbd 100644
--- a/drivers/mmc/host/bcm2835.c
+++ b/drivers/mmc/host/bcm2835.c
@@ -1393,7 +1393,17 @@ static int bcm2835_probe(struct platform_device *pdev)
host->dma_chan = NULL;
host->dma_desc = NULL;

- host->dma_chan_rxtx = dma_request_slave_channel(dev, "rx-tx");
+ host->dma_chan_rxtx = dma_request_chan(dev, "rx-tx");
+ if (IS_ERR(host->dma_chan_rxtx)) {
+ ret = PTR_ERR(host->dma_chan_rxtx);
+ host->dma_chan_rxtx = NULL;
+
+ if (ret == -EPROBE_DEFER)
+ goto err;
+
+ /* Ignore errors to fall back to PIO mode */
+ }
+

clk = devm_clk_get(dev, NULL);
if (IS_ERR(clk)) {
--
Peter

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