| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.16 040/279] spi: cadence: Add usleep_range() for cdns_spi_fill_tx_fifo() | Date | Mon, 18 Jun 2018 10:10:25 +0200 |
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4.16-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
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