diff mbox

Applied "spi: cadence: Add usleep_range() for cdns_spi_fill_tx_fifo()" to the spi tree

Message ID E1f8kKp-0007Pp-0j@debutante (mailing list archive)
State Accepted
Commit 49530e6411789c1b9ea3ebc58e520c19d1c3752f
Headers show

Commit Message

Mark Brown April 18, 2018, 10:29 a.m. UTC 
The patch

   spi: cadence: Add usleep_range() for cdns_spi_fill_tx_fifo()

has been applied to the spi tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

From 49530e6411789c1b9ea3ebc58e520c19d1c3752f Mon Sep 17 00:00:00 2001
From: sxauwsk <sxauwsk@163.com>
Date: Tue, 17 Apr 2018 04:01:27 +0800
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 <sxauwsk@163.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 drivers/spi/spi-cadence.c | 8 ++++++++
 1 file changed, 8 insertions(+)
diff mbox

Patch

diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c
index 5c9516ae4942..4a001634023e 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