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Subject[PATCH 1/9] spi: atmel: Use dma_request_chan() instead dma_request_slave_channel()
Date
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>
---
drivers/spi/spi-atmel.c | 29 +++++++++++------------------
1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 56f0ca361deb..013458cabe3c 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -514,26 +514,19 @@ static int atmel_spi_configure_dma(struct spi_master *master,
master->dma_tx = dma_request_chan(dev, "tx");
if (IS_ERR(master->dma_tx)) {
err = PTR_ERR(master->dma_tx);
- if (err == -EPROBE_DEFER) {
- dev_warn(dev, "no DMA channel available at the moment\n");
- goto error_clear;
- }
- dev_err(dev,
- "DMA TX channel not available, SPI unable to use DMA\n");
- err = -EBUSY;
+ if (err != -EPROBE_DEFER)
+ dev_err(dev, "No TX DMA channel, DMA is disabled\n");
goto error_clear;
}

- /*
- * No reason to check EPROBE_DEFER here since we have already requested
- * tx channel. If it fails here, it's for another reason.
- */
- master->dma_rx = dma_request_slave_channel(dev, "rx");
-
- if (!master->dma_rx) {
- dev_err(dev,
- "DMA RX channel not available, SPI unable to use DMA\n");
- err = -EBUSY;
+ master->dma_rx = dma_request_chan(dev, "rx");
+ if (IS_ERR(master->dma_rx)) {
+ err = PTR_ERR(master->dma_rx);
+ /*
+ * No reason to check EPROBE_DEFER here since we have already
+ * requested tx channel.
+ */
+ dev_err(dev, "No RX DMA channel, DMA is disabled\n");
goto error;
}

@@ -548,7 +541,7 @@ static int atmel_spi_configure_dma(struct spi_master *master,

return 0;
error:
- if (master->dma_rx)
+ if (!IS_ERR(master->dma_rx))
dma_release_channel(master->dma_rx);
if (!IS_ERR(master->dma_tx))
dma_release_channel(master->dma_tx);
--
Peter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

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