From: Vineet Gupta vgupta@synopsys.com
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@vger.kernel.org Signed-off-by: Vineet Gupta vgupta@synopsys.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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