From 2c29113154f510e25485e8a41ef109f7c223cacf Mon Sep 17 00:00:00 2001 From: Larisa Grigore Date: Thu, 22 May 2025 15:51:32 +0100 Subject: [PATCH] spi: spi-fsl-dspi: Reset SR flags before sending a new message [ Upstream commit 7aba292eb15389073c7f3bd7847e3862dfdf604d ] If, in a previous transfer, the controller sends more data than expected by the DSPI target, SR.RFDF (RX FIFO is not empty) will remain asserted. When flushing the FIFOs at the beginning of a new transfer (writing 1 into MCR.CLR_TXF and MCR.CLR_RXF), SR.RFDF should also be cleared. Otherwise, when running in target mode with DMA, if SR.RFDF remains asserted, the DMA callback will be fired before the controller sends any data. Take this opportunity to reset all Status Register fields. Fixes: 5ce3cc567471 ("spi: spi-fsl-dspi: Provide support for DSPI slave mode operation (Vybryd vf610)") Signed-off-by: Larisa Grigore Signed-off-by: James Clark Link: https://patch.msgid.link/20250522-james-nxp-spi-v2-3-bea884630cfb@linaro.org Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-fsl-dspi.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index 93cdc52f0fb06..5374c6d44519a 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -956,6 +956,8 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr, SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF, SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF); + regmap_write(dspi->regmap, SPI_SR, SPI_SR_CLEAR); + spi_take_timestamp_pre(dspi->ctlr, dspi->cur_transfer, dspi->progress, !dspi->irq); -- 2.47.3