[PATCH] perf/arm-cmn: Fix {wp_dev_sel2, wp_dev_sel} limited to 0/1 when MXP_MULTIPLE_DTM_EN is TRUE
allen.wang
allen.wang at hj-micro.com
Tue Sep 8 01:15:08 PDT 2026
Hi,
Gentle ping on this patch.
Could someone please review it when time permits?
Thanks!
Allen
On 8/19/2026 6:54 PM, Shouping Wang wrote:
> When MXP_MULTIPLE_DTM_EN is TRUE, each DTM will monitor at most
> two device ports. In this case, {wp_dev_sel2, wp_dev_sel} will
> only use values 2'b00 and 2'b01 per DTM.
>
> Previously the setting allowed values beyond the supported range
> per DTM, which could cause each DTM to select invalid ports when
> MXP_MULTIPLE_DTM_EN is TRUE.
>
> Fix this by applying `dev %= 2` to clamp the selection value to
> the valid range when MXP_MULTIPLE_DTM_EN is TRUE.
>
> Fixes: 60d1504070c2 ("perf/arm-cmn: Support new IP features")
> Signed-off-by: Shouping Wang <allen.wang at hj-micro.com>
> ---
> drivers/perf/arm-cmn.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/perf/arm-cmn.c b/drivers/perf/arm-cmn.c
> index 40c05c519a1d..13ccbf2a7345 100644
> --- a/drivers/perf/arm-cmn.c
> +++ b/drivers/perf/arm-cmn.c
> @@ -1392,6 +1392,7 @@ static void arm_cmn_claim_wp_idx(struct arm_cmn_dtm *dtm,
>
> static u32 arm_cmn_wp_config(struct perf_event *event, int wp_idx)
> {
> + struct arm_cmn *cmn = to_cmn(event->pmu);
> u32 config;
> u32 dev = CMN_EVENT_WP_DEV_SEL(event);
> u32 chn = CMN_EVENT_WP_CHN_SEL(event);
> @@ -1404,6 +1405,9 @@ static u32 arm_cmn_wp_config(struct perf_event *event, int wp_idx)
> if (is_cmn600)
> grp &= 1;
>
> + if (cmn->multi_dtm)
> + dev %= 2;
> +
> config = FIELD_PREP(CMN_DTM_WPn_CONFIG_WP_DEV_SEL, dev) |
> FIELD_PREP(CMN_DTM_WPn_CONFIG_WP_CHN_SEL, chn) |
> FIELD_PREP(CMN_DTM_WPn_CONFIG_WP_GRP, grp) |
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