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mtd: spi-nor: cadence-quadspi: Handle probe deferral while requesting DMA channel

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[ 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@ti.com>
Reviewed-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Acked-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20200601070444.16923-6-vigneshr@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Stable-dep-of: 2087e85bb66e ("spi: cadence-quadspi: fix suspend-resume implementations")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Vignesh Raghavendra 2020-06-01 12:34:41 +05:30 committed by Greg Kroah-Hartman
parent ee5ffe4cdf
commit caaefbf823
1 changed files with 13 additions and 5 deletions
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18
drivers/mtd/spi-nor/cadence-quadspi.c
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@ -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;
}
}
}