spi: rockchip: Signal unfinished DMA transfers
diff mbox

Message ID 1465371171-20810-1-git-send-email-tomeu.vizoso@collabora.com
State New
Headers show

Commit Message

Tomeu Vizoso June 8, 2016, 7:32 a.m. UTC
When using DMA, the transfer_one callback should return 1 because the
transfer hasn't finished yet.

A previous commit changed the function to return 0 when the DMA channels
were correctly prepared.

This manifested in Veyron boards with this message:

[ 1.983605] cros-ec-spi spi0.0: EC failed to respond in time

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Fixes: ea9849113343 ("spi: rockchip: check return value of
dmaengine_prep_slave_sg")
Cc: Shawn Lin <shawn.lin@rock-chips.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Javier Martinez Canillas <javier@osg.samsung.com>
---
 drivers/spi/spi-rockchip.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

Comments

Mark Brown June 8, 2016, 10:55 a.m. UTC | #1
On Wed, Jun 08, 2016 at 09:32:51AM +0200, Tomeu Vizoso wrote:

> +		/* successful DMA prepare means the transfer is in progress */
> +		ret = ret ? ret : 1;

Please write normal if statements so people can read the code more
easily.
Heiko Stuebner June 8, 2016, 12:26 p.m. UTC | #2
Am Mittwoch, 8. Juni 2016, 09:32:51 schrieb Tomeu Vizoso:
> When using DMA, the transfer_one callback should return 1 because the
> transfer hasn't finished yet.
> 
> A previous commit changed the function to return 0 when the DMA channels
> were correctly prepared.
> 
> This manifested in Veyron boards with this message:
> 
> [ 1.983605] cros-ec-spi spi0.0: EC failed to respond in time
> 
> Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
> Fixes: ea9849113343 ("spi: rockchip: check return value of
> dmaengine_prep_slave_sg")
> Cc: Shawn Lin <shawn.lin@rock-chips.com>
> Cc: Heiko Stuebner <heiko@sntech.de>
> Cc: Javier Martinez Canillas <javier@osg.samsung.com>

looks like Mark already applied it, but nevertheless I was able to verify that 
this patch fixes the issue on my veyron jerry chromebook as well, so

Tested-by: Heiko Stuebner <heiko@sntech.de>

Patch
diff mbox

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index cd89682065b9..1026e180eed7 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -578,7 +578,7 @@  static int rockchip_spi_transfer_one(
 		struct spi_device *spi,
 		struct spi_transfer *xfer)
 {
-	int ret = 1;
+	int ret = 0;
 	struct rockchip_spi *rs = spi_master_get_devdata(master);
 
 	WARN_ON(readl_relaxed(rs->regs + ROCKCHIP_SPI_SSIENR) &&
@@ -627,6 +627,8 @@  static int rockchip_spi_transfer_one(
 			spi_enable_chip(rs, 1);
 			ret = rockchip_spi_prepare_dma(rs);
 		}
+		/* successful DMA prepare means the transfer is in progress */
+		ret = ret ? ret : 1;
 	} else {
 		spi_enable_chip(rs, 1);
 		ret = rockchip_spi_pio_transfer(rs);