4.14-stable review patch. If anyone has any objections, please let me know.
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From: sxauwsk sxauwsk@163.com
[ Upstream commit 49530e6411789c1b9ea3ebc58e520c19d1c3752f ]
In case of xspi work in busy condition, may send bytes failed. once something wrong, spi controller did't work any more
My test found this situation appear in both of read/write process. so when TX FIFO is full, add one byte delay before send data;
Signed-off-by: sxauwsk sxauwsk@163.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/spi/spi-cadence.c | 8 ++++++++ 1 file changed, 8 insertions(+)
--- a/drivers/spi/spi-cadence.c +++ b/drivers/spi/spi-cadence.c @@ -313,6 +313,14 @@ static void cdns_spi_fill_tx_fifo(struct
while ((trans_cnt < CDNS_SPI_FIFO_DEPTH) && (xspi->tx_bytes > 0)) { + + /* When xspi in busy condition, bytes may send failed, + * then spi control did't work thoroughly, add one byte delay + */ + if (cdns_spi_read(xspi, CDNS_SPI_ISR) & + CDNS_SPI_IXR_TXFULL) + usleep_range(10, 20); + if (xspi->txbuf) cdns_spi_write(xspi, CDNS_SPI_TXD, *xspi->txbuf++); else