From: Vineet Gupta <vgupta@xxxxxxxxxxxx>
commit feb92d7d3813456c11dce215b3421801a78a8986 upstream.
Current code inadventely bails if hardware supports sampling/overflow
interrupts, but the irq is missing from device tree.
|
| # perf stat -e cycles,instructions,major-faults,minor-faults ../hackbench
| Running with 10 groups 400 process
| Time: 0.921
|
| Performance counter stats for '../hackbench':
|
| <not supported> cycles
| <not supported> instructions
| 0 major-faults
| 8679 minor-faults
This need not be as we can still do simple counting based perf stat.
This unborks perf on HSDK-4xD
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arc/kernel/perf_event.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)
--- a/arch/arc/kernel/perf_event.c
+++ b/arch/arc/kernel/perf_event.c
@@ -562,7 +562,7 @@ static int arc_pmu_device_probe(struct p
{
struct arc_reg_pct_build pct_bcr;
struct arc_reg_cc_build cc_bcr;
- int i, has_interrupts;
+ int i, has_interrupts, irq;
int counter_size; /* in bits */
union cc_name {
@@ -637,13 +637,7 @@ static int arc_pmu_device_probe(struct p
.attr_groups = arc_pmu->attr_groups,
};
- if (has_interrupts) {
- int irq = platform_get_irq(pdev, 0);
-
- if (irq < 0) {
- pr_err("Cannot get IRQ number for the platform\n");
- return -ENODEV;
- }
+ if (has_interrupts && (irq = platform_get_irq(pdev, 0) >= 0)) {
arc_pmu->irq = irq;
@@ -652,9 +646,9 @@ static int arc_pmu_device_probe(struct p
this_cpu_ptr(&arc_pmu_cpu));
on_each_cpu(arc_cpu_pmu_irq_init, &irq, 1);
-
- } else
+ } else {
arc_pmu->pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
+ }
/*
* perf parser doesn't really like '-' symbol in events name, so let's
