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Commit 5e9af37e authored by Ludovic Desroches's avatar Ludovic Desroches Committed by Mark Brown
Browse files

spi: atmel: introduce probe deferring 



Return probe defer if requesting a dma channel without a dma controller
probed.

Signed-off-by: default avatarLudovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 7758e390

drivers/spi/spi-atmel.c

+16 −4
Original line number Diff line number Diff line
@@ -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;

	}