[PATCH v3 1/3] i3c: add sysfs entry for Device NACK Retry count

[Frank Li]

On Sat, Nov 22, 2025 at 02:00:39AM +0800, adrianhoyin.ng at altera.com wrote:
> From: Adrian Ng Ho Yin <adrianhoyin.ng at altera.com>
>
> Document sysfs attribute dev_nack_retry_cnt that controls the number of
> automatic retries performed by the I3C controller when a target device
> returns a NACK
>
> Signed-off-by: Adrian Ng Ho Yin <adrianhoyin.ng at altera.com>
> ---

Reviewed-by: Frank Li <Frank.Li at nxp.com>

>  Documentation/ABI/testing/sysfs-bus-i3c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-i3c b/Documentation/ABI/testing/sysfs-bus-i3c
> index c812ab180ff4..0b8a0c223f4a 100644
> --- a/Documentation/ABI/testing/sysfs-bus-i3c
> +++ b/Documentation/ABI/testing/sysfs-bus-i3c
> @@ -161,3 +161,15 @@ Contact:	linux-i3c at vger.kernel.org
>  Description:
>  		These directories are just symbolic links to
>  		/sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>.
> +
> +What:		/sys/bus/i3c/devices/i3c-<bus-id>/<bus-id>-<device-pid>/dev_nack_retry_count
> +KernelVersion:  6.18
> +Contact:	linux-i3c at vger.kernel.org
> +Description:
> +		Expose the dev_nak_retry_count which controls the number of
> +		automatic retries that will be performed by the controller when
> +		the target device returns a NACK response. A value of 0 disables
> +		the automatic retries. A max value of 3 can be configured. Exist
> +		only when I3C constroller supports this retry on nack feature.
> +
> +		Valid values: 0-3
> --
> 2.49.GIT
>