[PATCH 4/8] PM / devfreq: rockchip-dfi: add NO_INTERRUPT perf capability

[Sebastian Reichel]

From: Nicolas Frattaroli <nicolas.frattaroli@xxxxxxxxxxxxx>

The perf subsystem's PERF_PMU_CAP_NO_INTERRUPT is a bit of a
misnomer.[1] Instead of meaning that the PMU has no interrupt, it
actually means that the PMU does support sampling. On CPU PMUs, this is
equivalent to not having an interrupt, but for uncore PMUs like the
rockchip-dfi PMU is, no meaningful sample data could ever be generated
regardless of whether or not there is an interrupt, as it is not a CPU.

Since rockchip-dfi doesn't seem to make use of the interrupt the DT
provides it with anyway, this was probably never a confusion that
existed in this case; the capability flag was likely just forgotten.

Add PERF_PMU_CAP_NO_INTERRUPT to the set flags for the pmu struct's
capabilities member, so that the perf core knows about this limitation.

Fixes: 4d586b5724d3 ("PM / devfreq: rockchip-dfi: Add perf support")
Link: https://lore.kernel.org/all/20250619140442.GH1613376@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ [1]
Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@xxxxxxxxxxxxx>
Signed-off-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
---
 drivers/devfreq/event/rockchip-dfi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/devfreq/event/rockchip-dfi.c b/drivers/devfreq/event/rockchip-dfi.c
index 5339616f7ca6..dd9edfd6a674 100644
--- a/drivers/devfreq/event/rockchip-dfi.c
+++ b/drivers/devfreq/event/rockchip-dfi.c
@@ -646,7 +646,7 @@ static int rockchip_ddr_perf_init(struct rockchip_dfi *dfi)
 	seqlock_init(&dfi->count_seqlock);
 
 	pmu->module = THIS_MODULE;
-	pmu->capabilities = PERF_PMU_CAP_NO_EXCLUDE;
+	pmu->capabilities = PERF_PMU_CAP_NO_EXCLUDE | PERF_PMU_CAP_NO_INTERRUPT;
 	pmu->task_ctx_nr = perf_invalid_context;
 	pmu->attr_groups = attr_groups;
 	pmu->event_init  = rockchip_ddr_perf_event_init;

-- 
2.53.0