diff options
| author | Ludovic Desroches <ludovic.desroches@atmel.com> | 2014-11-14 19:12:54 +0300 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2014-11-24 21:57:37 +0300 |
| commit | 5e9af37e46bceea9f950d2f2ae769f1aa6b6d7a6 (patch) | |
| tree | b84f57b2f8d55233718e9be05795e1e61853ac25 | |
| parent | 7758e390699fb25bf91642d52734200db38e764b (diff) | |
| download | linux-5e9af37e46bceea9f950d2f2ae769f1aa6b6d7a6.tar.xz | |
spi: atmel: introduce probe deferring
Return probe defer if requesting a dma channel without a dma controller
probed.
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
| -rw-r--r-- | drivers/spi/spi-atmel.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c index 3370a3dfd883..e4193ccc4970 100644 --- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -427,14 +427,23 @@ static int atmel_spi_configure_dma(struct atmel_spi *as) dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); - as->dma.chan_tx = dma_request_slave_channel(dev, "tx"); - if (!as->dma.chan_tx) { + as->dma.chan_tx = dma_request_slave_channel_reason(dev, "tx"); + if (IS_ERR(as->dma.chan_tx)) { + err = PTR_ERR(as->dma.chan_tx); + if (err == -EPROBE_DEFER) { + dev_warn(dev, "no DMA channel available at the moment\n"); + return err; + } dev_err(dev, "DMA TX channel not available, SPI unable to use DMA\n"); err = -EBUSY; goto error; } + /* + * No reason to check EPROBE_DEFER here since we have already requested + * tx channel. If it fails here, it's for another reason. + */ as->dma.chan_rx = dma_request_slave_channel(dev, "rx"); if (!as->dma.chan_rx) { @@ -456,7 +465,7 @@ static int atmel_spi_configure_dma(struct atmel_spi *as) error: if (as->dma.chan_rx) dma_release_channel(as->dma.chan_rx); - if (as->dma.chan_tx) + if (!IS_ERR(as->dma.chan_tx)) dma_release_channel(as->dma.chan_tx); return err; } @@ -1328,8 +1337,11 @@ static int atmel_spi_probe(struct platform_device *pdev) as->use_dma = false; as->use_pdc = false; if (as->caps.has_dma_support) { - if (atmel_spi_configure_dma(as) == 0) + ret = atmel_spi_configure_dma(as); + if (ret == 0) as->use_dma = true; + else if (ret == -EPROBE_DEFER) + return ret; } else { as->use_pdc = true; } |