Re: [PATCH drivers/perf: hisi: 2/2] drivers/perf: hisi: fix set wrong filter mode for running events issue

[Will Deacon]

[+Guangbin Huang and Shaokun Zhang]

On Wed, Aug 16, 2023 at 05:46:19PM +0800, Jijie Shao wrote:
> From: Hao Chen <chenhao418@xxxxxxxxxx>
> 
> hns3_pmu_select_filter_mode() includes a series of mode judgments such
> as global mode ,function mode, function-queue mode, port mode, port-tc
> mode.
> 
> For a special scenario, command use parameter "bdf=0x3700,config=0x3,
> queue=0x0", it is expected to enter function-queue mode, but event of
> config 0x3 doesn't support func-queue mode, then it enter port-tc mode.
> it's not up to expectations.
> 
> It shouldn't enter any modes but return -ENOENT.
> 
> So, add judgement of bdf parameter to fix it.
> 
> Fixes: 66637ab137b4 ("drivers/perf: hisi: add driver for HNS3 PMU")
> Signed-off-by: Hao Chen <chenhao418@xxxxxxxxxx>
> Signed-off-by: Jijie Shao <shaojijie@xxxxxxxxxx>
> ---
>  drivers/perf/hisilicon/hns3_pmu.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/perf/hisilicon/hns3_pmu.c b/drivers/perf/hisilicon/hns3_pmu.c
> index 6a4d04cbae91..7f38a9e489d4 100644
> --- a/drivers/perf/hisilicon/hns3_pmu.c
> +++ b/drivers/perf/hisilicon/hns3_pmu.c
> @@ -1000,12 +1000,13 @@ static bool
>  hns3_pmu_is_enabled_port_tc_mode(struct perf_event *event,
>  				 struct hns3_pmu_event_attr *pmu_event)
>  {
> +	u16 bdf = hns3_pmu_get_bdf(event);
>  	u8 tc_id = hns3_pmu_get_tc(event);
>  
>  	if (!(pmu_event->filter_support & HNS3_PMU_FILTER_SUPPORT_PORT_TC))
>  		return false;
>  
> -	return tc_id != HNS3_PMU_FILTER_ALL_TC;
> +	return (tc_id != HNS3_PMU_FILTER_ALL_TC) && (!bdf);
>  }

Sorry, but I'm struggling to see how this correlates with your example
in the commit message, which implies that it's the config of 0x3 causing
the problem rather than the bdf.

Please can you explain the problem in more detail?

Thanks,

Will