Re: [PATCH v4 2/2] i2c: core: support recovery for single-ended GPIOs

[Wolfram Sang]

On Sat, May 09, 2026 at 11:12:08AM +0200, Jie Li wrote:
> Currently, i2c_init_recovery() only assigns the set_sda/set_scl
> hooks if gpiod_get_direction() returns GPIO_LINE_DIRECTION_OUT.
> 
> This logic fails on certain SoC controllers where open-drain lines
> in a high-impedance state are physically reported as inputs. This
> leads to a "deadlock" where the I2C core refuses to assign the
> recovery hooks because it incorrectly assumes the pins are
> input-only, even though they are fully capable of driving the bus
> low for recovery.
> 
> Update the recovery initialization to use the new
> gpiod_is_single_ended() helper. If a GPIO is configured as
> open-drain or open-source in the firmware, it is safe to assume
> it can be used for bus recovery, even if the current hardware
> direction is reported as input.
> 
> Signed-off-by: Jie Li <jie.i.li@xxxxxxxxx>
> Reviewed-by: Linus Walleij <linusw@xxxxxxxxxx>
> Acked-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>

I overlooked that the change with GPIO_LINE_DIRECTION_OUT I suggested
for this patch is at the same location as commit[1]. I already pushed
out said commit for -rc3 and it is, thus, already in -next, too. No big
harm, but there will be a little conflict when applying. Sorry, Linus!

[1] b47bc7c022dd ("i2c: Compare the return value of gpiod_get_direction against GPIO_LINE_DIRECTION_OUT")

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