From c6c1e30a789b08de2e075cbd9705e81af3d2c7cc Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Wed, 18 Mar 2020 02:15:55 +0200 Subject: [PATCH] spi: spi-fsl-dspi: Avoid reading more data than written in EOQ mode If dspi->words_in_flight is populated with the hardware FIFO size, then in dspi_fifo_read it will attempt to read more data at the end of a buffer that is not a multiple of 16 bytes in length. It will probably time out attempting to do so. So limit the num_fifo_entries variable to the actual number of FIFO entries that is going to be used. Fixes: d59c90a2400f ("spi: spi-fsl-dspi: Convert TCFQ users to XSPI FIFO mode") Signed-off-by: Vladimir Oltean Tested-by: Michael Walle Link: https://lore.kernel.org/r/20200318001603.9650-5-olteanv@gmail.com Signed-off-by: Mark Brown --- drivers/spi/spi-fsl-dspi.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index 8f2b73cc6ed7..51224b772680 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -739,13 +739,16 @@ static void dspi_eoq_fifo_write(struct fsl_dspi *dspi) int num_fifo_entries = dspi->devtype_data->fifo_size; u16 xfer_cmd = dspi->tx_cmd; + if (num_fifo_entries * dspi->oper_word_size > dspi->len) + num_fifo_entries = dspi->len / dspi->oper_word_size; + dspi->words_in_flight = num_fifo_entries; /* Fill TX FIFO with as many transfers as possible */ - while (dspi->len && num_fifo_entries--) { + while (num_fifo_entries--) { dspi->tx_cmd = xfer_cmd; /* Request EOQF for last transfer in FIFO */ - if (dspi->len == dspi->oper_word_size || num_fifo_entries == 0) + if (num_fifo_entries == 0) dspi->tx_cmd |= SPI_PUSHR_CMD_EOQ; /* Write combined TX FIFO and CMD FIFO entry */ dspi_pushr_write(dspi);