On Sat, Jun 16, 2018 at 09:56:36PM +0900, Wolfram Sang wrote:
> It seems that during the conversion from gpio* to gpiod*, the initial
> state of SCL was wrongly switched to LOW. Fix it to be HIGH again.
>
> Fixes: 7bb75029ef34 ("i2c: gpio: Enforce open drain through gpiolib")
> Signed-off-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> ---
>
> Linus: Or was it intentional? But then I am missing something... I found this
> by trying to fix a regression. I can't scope my use case now because I am on
> the road. I recall SCL being unexpectedly LOW when using the GPIO fault
> injector the last time, though. This made me do a fix in the underlying
> i2c-algo-bit algorithm, but that sadly caused a regression :( So, this may be
> the proper fix. RFC for now, until I have my scope back. But discussion is
> welcome.
Linus: any comment?
>
> drivers/i2c/busses/i2c-gpio.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c
> index 005e6e0330c2..66f85bbf3591 100644
> --- a/drivers/i2c/busses/i2c-gpio.c
> +++ b/drivers/i2c/busses/i2c-gpio.c
> @@ -279,9 +279,9 @@ static int i2c_gpio_probe(struct platform_device *pdev)
> * required for an I2C bus.
> */
> if (pdata->scl_is_open_drain)
> - gflags = GPIOD_OUT_LOW;
> + gflags = GPIOD_OUT_HIGH;
> else
> - gflags = GPIOD_OUT_LOW_OPEN_DRAIN;
> + gflags = GPIOD_OUT_HIGH_OPEN_DRAIN;
> priv->scl = i2c_gpio_get_desc(dev, "scl", 1, gflags);
> if (IS_ERR(priv->scl))
> return PTR_ERR(priv->scl);
> --
> 2.11.0
>
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