[PATCH v4 1/4] spi: spi-fsl-dspi: Fix lockup if device is removed during SPI transfer

Krzysztof Kozlowski
2020-06-22T11:05:55Z

During device removal, the driver should unregister the SPI controller
and stop the hardware. Otherwise the dspi_transfer_one_message() could
wait on completion infinitely.

Additionally, calling spi_unregister_controller() first in device
removal reverse-matches the probe function, where SPI controller is
registered at the end.

Fixes: 05209f457069 ("spi: fsl-dspi: add missing clk_disable_unprepare() in dspi_remove()")
Cc: <stable@vger.kernel.org>
Reported-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

---

Changes since v3:
1. New patch.
---
drivers/spi/spi-fsl-dspi.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 58190c94561f..ec0fd0d366eb 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -1434,9 +1434,18 @@ static int dspi_remove(struct platform_device *pdev)
struct fsl_dspi *dspi = spi_controller_get_devdata(ctlr);

/* Disconnect from the SPI framework */
+ spi_unregister_controller(dspi->ctlr);
+
+ /* Disable RX and TX */
+ regmap_update_bits(dspi->regmap, SPI_MCR,
+ SPI_MCR_DIS_TXF | SPI_MCR_DIS_RXF,
+ SPI_MCR_DIS_TXF | SPI_MCR_DIS_RXF);
+
+ /* Stop Running */
+ regmap_update_bits(dspi->regmap, SPI_MCR, SPI_MCR_HALT, SPI_MCR_HALT);
+
dspi_release_dma(dspi);
clk_disable_unprepare(dspi->clk);
- spi_unregister_controller(dspi->ctlr);

return 0;
}
--
2.17.1