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-König <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)) { dev_dbg(&i2c_imx->adapter.dev,