From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rabin Vincent Subject: [PATCH] spi: pl022: handle EPROBE_DEFER for dma Date: Mon, 23 Nov 2015 08:13:45 +0100 Message-ID: <1448262825-19710-1-git-send-email-rabin.vincent@axis.com> Mime-Version: 1.0 Content-Type: text/plain Cc: , Rabin Vincent To: Return-path: Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: 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 --- drivers/spi/spi-pl022.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c index 94af806..5e5fd77 100644 --- a/drivers/spi/spi-pl022.c +++ b/drivers/spi/spi-pl022.c @@ -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_rx_channel = chan; - pl022->dma_tx_channel = dma_request_slave_channel(dev, "tx"); - if (!pl022->dma_tx_channel) + 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) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html