From: Vignesh Raghavendra <vigneshr@xxxxxx> [ Upstream commit 935da5e5100f57d843cac4781b21f1c235059aa0 ] dma_request_chan_by_mask() can throw EPROBE_DEFER if DMA provider is not yet probed. Currently driver just falls back to using PIO mode (which is less efficient) in this case. Instead return probe deferral error as is so that driver will be re probed once DMA provider is available. Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx> Reviewed-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx> Acked-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200601070444.16923-6-vigneshr@xxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Stable-dep-of: 2087e85bb66e ("spi: cadence-quadspi: fix suspend-resume implementations") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/mtd/spi-nor/cadence-quadspi.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c index ad27d3e4c5dbc..2c5a6587f505e 100644 --- a/drivers/mtd/spi-nor/cadence-quadspi.c +++ b/drivers/mtd/spi-nor/cadence-quadspi.c @@ -1168,7 +1168,7 @@ static void cqspi_controller_init(struct cqspi_st *cqspi) cqspi_controller_enable(cqspi, 1); } -static void cqspi_request_mmap_dma(struct cqspi_st *cqspi) +static int cqspi_request_mmap_dma(struct cqspi_st *cqspi) { dma_cap_mask_t mask; @@ -1177,11 +1177,16 @@ static void cqspi_request_mmap_dma(struct cqspi_st *cqspi) cqspi->rx_chan = dma_request_chan_by_mask(&mask); if (IS_ERR(cqspi->rx_chan)) { - dev_err(&cqspi->pdev->dev, "No Rx DMA available\n"); + int ret = PTR_ERR(cqspi->rx_chan); + + if (ret != -EPROBE_DEFER) + dev_err(&cqspi->pdev->dev, "No Rx DMA available\n"); cqspi->rx_chan = NULL; - return; + return ret; } init_completion(&cqspi->rx_dma_complete); + + return 0; } static int cqspi_setup_flash(struct cqspi_st *cqspi, struct device_node *np) @@ -1265,8 +1270,11 @@ static int cqspi_setup_flash(struct cqspi_st *cqspi, struct device_node *np) dev_dbg(nor->dev, "using direct mode for %s\n", mtd->name); - if (!cqspi->rx_chan) - cqspi_request_mmap_dma(cqspi); + if (!cqspi->rx_chan) { + ret = cqspi_request_mmap_dma(cqspi); + if (ret == -EPROBE_DEFER) + goto err; + } } } -- 2.39.2
