Re: [PATCH v2 8/9] i2c: riic: Add `riic_bus_barrier()` to check bus availability

[Wolfram Sang]

On Wed, Dec 18, 2024 at 12:16:17AM +0000, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> 
> Introduce a new `riic_bus_barrier()` function to verify bus availability
> before initiating an I2C transfer. This function enhances the bus
> arbitration check by ensuring that the SDA and SCL lines are not held low,
> in addition to checking the BBSY flag using `readb_poll_timeout()`.
> 
> Previously, only the BBSY flag was checked to determine bus availability.
> However, it is possible for the SDA line to remain low even when BBSY = 0.
> This new implementation performs an additional check on the SDA and SCL
> lines to avoid potential bus contention issues.
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

...

> -	if (riic_readb(riic, RIIC_ICCR2) & ICCR2_BBSY) {
> -		riic->err = -EBUSY;
> +	riic->err = riic_bus_barrier(riic);
> +	if (riic->err)
>  		goto out;
> -	}
>  
>  	reinit_completion(&riic->msg_done);
>  	riic->err = 0;

This initialization can go now. err is 0 already.

With that fixed:

Reviewed-by: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>

Attachment: signature.asc
Description: PGP signature