Subject: Re: [PATCH net v2 1/1] net: stmmac: Fix zero-division error when disabling tc cbs

From: Simon Horman <[email-masked]>
Date: Wed, 18 Sep 2024 08:06:49 +0100

On Wed, Sep 18, 2024 at 02:14:22PM +0800, KhaiWenTan wrote:
> The commit b8c43360f6e4 ("net: stmmac: No need to calculate speed divider
> when offload is disabled") allows the "port_transmit_rate_kbps" to be
> set to a value of 0, which is then passed to the "div_s64" function when
> tc-cbs is disabled. This leads to a zero-division error.
> 
> When tc-cbs is disabled, the idleslope, sendslope, and credit values the
> credit values are not required to be configured. Therefore, adding a return
> statement after setting the txQ mode to DCB when tc-cbs is disabled would
> prevent a zero-division error.
> 
> Fixes: b8c43360f6e4 ("net: stmmac: No need to calculate speed divider when offload is disabled")
> Cc: <[email-masked]>
> Co-developed-by: Choong Yong Liang <[email-masked]>
> Signed-off-by: Choong Yong Liang <[email-masked]>
> Signed-off-by: KhaiWenTan <[email-masked]>
> ---
> v2:
>   - reflected code for better understanding
> v1: https://patchwork.kernel.org/project/netdevbpf/patch/[email-masked]/

Thanks for the update.

Reviewed-by: Simon Horman <[email-masked]>