2018-04-18 01:18:38

by [email protected]

[permalink] [raw]
Subject: [PATCH] spi: cadence: Add usleep_range() for cdns_spi_fill_tx_fifo()

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 <[email protected]>
---
drivers/spi/spi-cadence.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c
index 5c9516a..4a00163 100644
--- a/drivers/spi/spi-cadence.c
+++ b/drivers/spi/spi-cadence.c
@@ -313,6 +313,14 @@ 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,
+ * 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
--
1.7.9.5