Re: [PATCH v1 03/11] arm_mpam: Set mpam_feat_msmon_mbwu_31counter when there are bandwidth counters

[Shaopeng Tan (Fujitsu)]

Hello Ben,

>If there are memory bandwidth counters then there are 31 bit counters even
>if there are also 44 bit counters or 63 bit counters.

Although 31-bit counters are always exist, aren't they never used simultaneously with 44-bit or 63-bit counters?
If the `mpam_feat_msmon_mbwu_31counter` feature is set to always be enabled, could that potentially cause a bug?

Best regards,
Shaopeng TAN


>Set the 31 bit bandwidth counter feature bit whenever there are bandwidth
>counters.
>
>Fixes: fdc29a141d63 ("arm_mpam: Probe for long/lwd mbwu counters")
>Signed-off-by: Ben Horgan <ben.horgan@xxxxxxx>
>---
> drivers/resctrl/mpam_devices.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
>diff --git a/drivers/resctrl/mpam_devices.c b/drivers/resctrl/mpam_devices.c
>index acfa9a4dc2fc..11b10c3bc334 100644
>--- a/drivers/resctrl/mpam_devices.c
>+++ b/drivers/resctrl/mpam_devices.c
>@@ -930,9 +930,9 @@ static void mpam_ris_hw_probe(struct mpam_msc_ris *ris)
>                                                 mpam_set_feature(mpam_feat_msmon_mbwu_63counter, props);
>                                         else
>                                                 mpam_set_feature(mpam_feat_msmon_mbwu_44counter, props);
>-                               } else {
>-                                       mpam_set_feature(mpam_feat_msmon_mbwu_31counter, props);
>                                 }
>+
>+                               mpam_set_feature(mpam_feat_msmon_mbwu_31counter, props);
>                         }
>                 }
>         }
>-- 
>2.43.0
>