6.7-stable review patch. If anyone has any objections, please let me know.
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From: Amit Kumar Mahapatra amit.kumar-mahapatra@amd.com
[ Upstream commit 633cd6fe6e1993ba80e0954c2db127a0b1a3e66f ]
In the existing implementation, when executing interleaved write and read operations in the ISR for a transfer length greater than the FIFO size, the TXFIFO write precedes the RXFIFO read. Consequently, the initially received data in the RXFIFO is pushed out and lost, leading to a failure in data integrity. To address this issue, reverse the order of interleaved operations and conduct the RXFIFO read followed by the TXFIFO write.
Fixes: 6afe2ae8dc48 ("spi: spi-cadence: Interleave write of TX and read of RX FIFO") Signed-off-by: Amit Kumar Mahapatra amit.kumar-mahapatra@amd.com Link: https://msgid.link/r/20231218090652.18403-1-amit.kumar-mahapatra@amd.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-cadence.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c index a50eb4db79de..e5140532071d 100644 --- a/drivers/spi/spi-cadence.c +++ b/drivers/spi/spi-cadence.c @@ -317,6 +317,15 @@ static void cdns_spi_process_fifo(struct cdns_spi *xspi, int ntx, int nrx) xspi->rx_bytes -= nrx;
while (ntx || nrx) { + if (nrx) { + u8 data = cdns_spi_read(xspi, CDNS_SPI_RXD); + + if (xspi->rxbuf) + *xspi->rxbuf++ = data; + + nrx--; + } + if (ntx) { if (xspi->txbuf) cdns_spi_write(xspi, CDNS_SPI_TXD, *xspi->txbuf++); @@ -326,14 +335,6 @@ static void cdns_spi_process_fifo(struct cdns_spi *xspi, int ntx, int nrx) ntx--; }
- if (nrx) { - u8 data = cdns_spi_read(xspi, CDNS_SPI_RXD); - - if (xspi->rxbuf) - *xspi->rxbuf++ = data; - - nrx--; - } } }