[RFC PATCH v4 5/6] i2c: rcar: skip DMA if buffer is not safe
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
Date: 2017-08-17 14:15:51
Also in:
dri-devel, linux-i2c, linux-iio, linux-media, linux-renesas-soc, lkml
Subsystem:
i2c subsystem, i2c subsystem host drivers, renesas r-car i2c drivers, the rest · Maintainers:
Wolfram Sang, Andi Shyti, Linus Torvalds
This HW is prone to races, so it needs to setup new messages in irq context. That means we can't alloc bounce buffers if a message buffer is not DMA safe. So, in that case, simply fall back to PIO. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- drivers/i2c/busses/i2c-rcar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index 93c1a54981df08..5654a7142bffec 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c@@ -359,7 +359,7 @@ static void rcar_i2c_dma(struct rcar_i2c_priv *priv) int len; /* Do not use DMA if it's not available or for messages < 8 bytes */ - if (IS_ERR(chan) || msg->len < 8) + if (IS_ERR(chan) || msg->len < 8 || !(msg->flags & I2C_M_DMA_SAFE)) return; if (read) {
--
2.11.0