Re: [PATCH net] net: sparx5: fix source port register when mirroring
From: Simon Horman
Date: Wed Oct 09 2024 - 10:02:41 EST
On Wed, Oct 09, 2024 at 02:49:56PM +0200, Daniel Machon wrote:
> When port mirroring is added to a port, the bit position of the source
> port, needs to be written to the register ANA_AC_PROBE_PORT_CFG. This
> register is replicated for n_ports > 32, and therefore we need to derive
> the correct register from the port number.
>
> Before this patch, we wrongly calculate the register from portno /
> BITS_PER_BYTE, where the divisor ought to be 32, causing any port >=8 to
> be written to the wrong register. We fix this, by using do_div(), where
> the dividend is the register, the remainder is the bit position and the
> divisor is now 32.
>
> Fixes: 4e50d72b3b95 ("net: sparx5: add port mirroring implementation")
> Signed-off-by: Daniel Machon <daniel.machon@xxxxxxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
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