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spi: pl022: handle EPROBE_DEFER for dma

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Handle EPROBE_DEFER explicitly so that we ensure that we get the DMA
channel specified in the device tree, instead of depending on the DMA
controller getting probed before us.

Signed-off-by: Rabin Vincent <rabin.vincent@axis.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Rabin Vincent 2015-11-23 08:13:45 +01:00 committed by Mark Brown
parent 8005c49d9a
commit f3d4bb3342
1 changed files with 22 additions and 6 deletions
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28
drivers/spi/spi-pl022.c
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@ -1171,19 +1171,31 @@ err_no_rxchan:
static int pl022_dma_autoprobe(struct pl022 *pl022)
{
struct device *dev = &pl022->adev->dev;
struct dma_chan *chan;
int err;
/* automatically configure DMA channels from platform, normally using DT */
pl022->dma_rx_channel = dma_request_slave_channel(dev, "rx");
if (!pl022->dma_rx_channel)
chan = dma_request_slave_channel_reason(dev, "rx");
if (IS_ERR(chan)) {
err = PTR_ERR(chan);
goto err_no_rxchan;
}
pl022->dma_tx_channel = dma_request_slave_channel(dev, "tx");
if (!pl022->dma_tx_channel)
pl022->dma_rx_channel = chan;
chan = dma_request_slave_channel_reason(dev, "tx");
if (IS_ERR(chan)) {
err = PTR_ERR(chan);
goto err_no_txchan;
}
pl022->dma_tx_channel = chan;
pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
if (!pl022->dummypage)
if (!pl022->dummypage) {
err = -ENOMEM;
goto err_no_dummypage;
}
return 0;
@ -1194,7 +1206,7 @@ err_no_txchan:
dma_release_channel(pl022->dma_rx_channel);
pl022->dma_rx_channel = NULL;
err_no_rxchan:
return -ENODEV;
return err;
}
static void terminate_dma(struct pl022 *pl022)
@ -2236,6 +2248,10 @@ static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
/* Get DMA channels, try autoconfiguration first */
status = pl022_dma_autoprobe(pl022);
if (status == -EPROBE_DEFER) {
dev_dbg(dev, "deferring probe to get DMA channel\n");
goto err_no_irq;
}
/* If that failed, use channels from platform_info */
if (status == 0)