[PATCH 3.16 208/233] i2c: imx: Use correct function to write to register

From: Ben Hutchings
Date: Sat Sep 09 2017 - 18:27:13 EST

3.16.48-rc1 review patch. If anyone has any objections, please let me know.


From: Michail Georgios Etairidis <m.etairidis@xxxxxxxxxxxx>

commit 6c782a5ea56a799658e213a78dc1455264938afa upstream.

The i2c-imx driver incorrectly uses readb()/writeb() to read and
write to the appropriate registers when performing a repeated start.
The appropriate imx_i2c_read_reg()/imx_i2c_write_reg() functions
should be used instead. Performing a repeated start results in
a kernel panic. The platform is imx.

Signed-off-by: Michail G Etairidis <m.etairidis@xxxxxxxxxxxx>
Fixes: ce1a78840ff7 ("i2c: imx: add DMA support for freescale i2c driver")
Fixes: 054b62d9f25c ("i2c: imx: fix the i2c bus hang issue when do repeat restart")
Acked-by: Fugang Duan <fugang.duan@xxxxxxx>
Acked-by: Uwe Kleine-KÃnig <u.kleine-koenig@xxxxxxxxxxxxxx>
Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx>
[bwh: Backported to 3.16: drop changes in i2c_imx_dma_read()]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -542,9 +542,9 @@ static int i2c_imx_read(struct imx_i2c_s
* the first read operation, otherwise the first read cost
* one extra clock cycle.
- temp = readb(i2c_imx->base + IMX_I2C_I2CR);
+ temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
temp |= I2CR_MTX;
- writeb(temp, i2c_imx->base + IMX_I2C_I2CR);
+ imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
} else if (i == (msgs->len - 2)) {