Re: [PATCH] perf/arm-cmn: Fix arm_cmn_node_to_xp()

[Namhyung Kim <namhyung@kernel.org>]

Hello,

On Wed, Nov 20, 2024 at 04:55:04PM +0000, Robin Murphy wrote:
> On 20/11/2024 4:41 pm, Namhyung Kim wrote:
> > The portid_bits and deviceid_bits for XP type nodes are set in the
> > arm_cmn_discover() and it's copied to others in arm_cmn_init_dtcs().
> > But to get the XP from a node in the arm_cmn_init_dtcs(), it needs
> > the {port,device}id_bits.
> > 
> > This makes arm-cmn PMU failing to count events on my setup.  What we
> > need is the number of bits in total which is known by the cmn config.
> 
> Hmm, what about just moving the assignment to a point where it actually
> makes more sense anyway?

Yep, this looks good to me too.  Do you want to me to resend this?

Thanks,
Namhyung

> 
> ----->8-----
> diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
> index 397a46410f7c..30506c43776f 100644
> --- a/drivers/perf/arm-cmn.c
> +++ b/drivers/perf/arm-cmn.c
> @@ -2178,8 +2178,6 @@ static int arm_cmn_init_dtcs(struct arm_cmn *cmn)
>  			continue;
>  		xp = arm_cmn_node_to_xp(cmn, dn);
> -		dn->portid_bits = xp->portid_bits;
> -		dn->deviceid_bits = xp->deviceid_bits;
>  		dn->dtc = xp->dtc;
>  		dn->dtm = xp->dtm;
>  		if (cmn->multi_dtm)
> @@ -2420,6 +2418,8 @@ static int arm_cmn_discover(struct arm_cmn *cmn, unsigned int rgn_offset)
>  			}
>  			arm_cmn_init_node_info(cmn, reg & CMN_CHILD_NODE_ADDR, dn);
> +			dn->portid_bits = xp->portid_bits;
> +			dn->deviceid_bits = xp->deviceid_bits;
>  			switch (dn->type) {
>  			case CMN_TYPE_DTC: