From: Michail Georgios Etairidis <m.etairidis@xxxxxxxxxxxx> [ Upstream commit 6c782a5ea56a799658e213a78dc1455264938afa ] 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-König <u.kleine-koenig@xxxxxxxxxxxxxx> Signed-off-by: Wolfram Sang <wsa@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- drivers/i2c/busses/i2c-imx.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index d4d853680ae4..c011e53c0b4d 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -746,9 +746,9 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, * 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); } msgs->buf[msgs->len-1] = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR); @@ -869,9 +869,9 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo * 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)) { dev_dbg(&i2c_imx->adapter.dev, -- 2.15.1