| From foo@baz Sun Jun 17 12:07:33 CEST 2018 |
| From: sxauwsk <sxauwsk@163.com> |
| Date: Tue, 17 Apr 2018 04:01:27 +0800 |
| Subject: spi: cadence: Add usleep_range() for cdns_spi_fill_tx_fifo() |
| |
| 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 |
