Re: [PATCH net v2 2/5] net: dsa: b53: fix the SRAB grant timeout check

[Daniel Machon]

> b53_srab_request_grant() polls for a grant up to 20 times, but checks for
> an iteration count of five to detect a timeout. This rejects a grant
> received on the sixth poll and reports success when all 20 polls finish
> without a grant. The latter allows a register access to proceed without
> ownership of the switch resources.
> 
> Check for exhaustion of all 20 iterations instead.
> 
> Fixes: 967dd82ffc52 ("net: dsa: b53: Add support for Broadcom RoboSwitch")
> Reviewed-by: Jonas Gorski <jonas.gorski@xxxxxxxxx>
> Signed-off-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
> ---
>  drivers/net/dsa/b53/b53_srab.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/dsa/b53/b53_srab.c b/drivers/net/dsa/b53/b53_srab.c
> index 83a03fca142a..f4689078ccd5 100644
> --- a/drivers/net/dsa/b53/b53_srab.c
> +++ b/drivers/net/dsa/b53/b53_srab.c
> @@ -105,7 +105,7 @@ static int b53_srab_request_grant(struct b53_device *dev)
>  			break;
>  		usleep_range(10, 100);
>  	}
> -	if (WARN_ON(i == 5))
> +	if (WARN_ON(i == 20))

I wondered why the initial check was i == 5. Seems like b53_srab_op(), just
below this one, has more or less the same loop, but with 5 iterations. Probably a
copy paste error.

>  		return -EIO;
>  
>  	return 0;
> -- 
> 2.53.0
> 

Reviewed-by: Daniel Machon <daniel.machon@xxxxxxxxxxxxx>