From 4f2f5d36d474a228d1f86045e4945432172ed4f7 Mon Sep 17 00:00:00 2001 From: Vignesh Raghavendra Date: Mon, 1 Jun 2020 12:34:41 +0530 Subject: [PATCH] mtd: spi-nor: cadence-quadspi: Handle probe deferral while requesting DMA channel [ Upstream commit 6ae9bf23828d11ed7bedb4aa1e25747fd93b3369 ] 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 Reviewed-by: Tudor Ambarus Acked-by: Tudor Ambarus Link: https://lore.kernel.org/r/20200601070444.16923-6-vigneshr@ti.com Signed-off-by: Mark Brown Stable-dep-of: 2087e85bb66e ("spi: cadence-quadspi: fix suspend-resume implementations") Signed-off-by: Sasha Levin --- 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; + } } } -- 2.39.5