In case of xspi work in busy condition, may send bytes failed.
Add one bytes delay
Signed-off-by: sxauwsk <[email protected]>
Signed-off-by: guojian <[email protected]>
Signed-off-by: wangshikai <[email protected]>
---
drivers/spi/spi-cadence.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c
index 5c9516a..66ae055 100644
--- a/drivers/spi/spi-cadence.c
+++ b/drivers/spi/spi-cadence.c
@@ -313,6 +313,12 @@ static void cdns_spi_fill_tx_fifo(struct cdns_spi *xspi)
while ((trans_cnt < CDNS_SPI_FIFO_DEPTH) &&
(xspi->tx_bytes > 0)) {
+
+ /* When xspi in busy condition, bytes may send failed,
+ * caused communication failure so add one byte delay
+ */
+ usleep_range(10, 20);
+
if (xspi->txbuf)
cdns_spi_write(xspi, CDNS_SPI_TXD, *xspi->txbuf++);
else
--
1.7.9.5
On Mon, Apr 09, 2018 at 07:16:50PM +0800, sxauwsk wrote:
> In case of xspi work in busy condition, may send bytes failed.
> Add one bytes delay
> while ((trans_cnt < CDNS_SPI_FIFO_DEPTH) &&
> (xspi->tx_bytes > 0)) {
> +
> + /* When xspi in busy condition, bytes may send failed,
> + * caused communication failure so add one byte delay
> + */
> + usleep_range(10, 20);
> +
> if (xspi->txbuf)
> cdns_spi_write(xspi, CDNS_SPI_TXD, *xspi->txbuf++);
This looks like it adds a byte of delay on every read/write - that
seems like a lot of overhead for something that sounds like it's
probably only an issue when the FIFO is full? Do we need to do this for
every operation, and is it needed for read or is it just write?