The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 7684580d45bd3d84ed9b453a4cadf7a9a5605a3f Mon Sep 17 00:00:00 2001

From: Krzysztof Kozlowski krzk@kernel.org Date: Mon, 22 Jun 2020 13:05:40 +0200 Subject: [PATCH] spi: spi-fsl-dspi: Fix lockup if device is removed during SPI transfer

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()") Reported-by: Vladimir Oltean olteanv@gmail.com Signed-off-by: Krzysztof Kozlowski krzk@kernel.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20200622110543.5035-1-krzk@kernel.org Signed-off-by: Mark Brown broonie@kernel.org

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; }