Hi Bjorn, Viresh,
On 4/7/22 23:09, Vladimir Zapolskiy wrote:
It's noted that dcvs interrupts are not self-clearing, thus an interrupt
handler runs constantly, which leads to a severe regression in runtime.
To fix the problem an explicit write to clear interrupt register is
required, note that on OSM platforms the register may not be present.
Fixes: 275157b367f4 ("cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support")
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@xxxxxxxxxx>
---
Changes from v2 to v3:
* split the change from the series and returned to v1 state of the fix
by removing a minor optimization
* added a check for non-zero reg_intr_clr value before writel
Changes from v1 to v2:
* added a check for pending interrupt status before its handling
drivers/cpufreq/qcom-cpufreq-hw.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index 0ec18e1589dc..0253731d6d25 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -24,6 +24,8 @@
#define CLK_HW_DIV 2
#define LUT_TURBO_IND 1
+#define GT_IRQ_STATUS BIT(2)
+
#define HZ_PER_KHZ 1000
struct qcom_cpufreq_soc_data {
@@ -32,6 +34,7 @@ struct qcom_cpufreq_soc_data {
u32 reg_dcvs_ctrl;
u32 reg_freq_lut;
u32 reg_volt_lut;
+ u32 reg_intr_clr;
u32 reg_current_vote;
u32 reg_perf_state;
u8 lut_row_size;
@@ -360,6 +363,10 @@ static irqreturn_t qcom_lmh_dcvs_handle_irq(int irq, void *data)
disable_irq_nosync(c_data->throttle_irq);
schedule_delayed_work(&c_data->throttle_work, 0);
+ if (c_data->soc_data->reg_intr_clr)
+ writel_relaxed(GT_IRQ_STATUS,
+ c_data->base + c_data->soc_data->reg_intr_clr);
+
return IRQ_HANDLED;
}
@@ -379,6 +386,7 @@ static const struct qcom_cpufreq_soc_data epss_soc_data = {
.reg_dcvs_ctrl = 0xb0,
.reg_freq_lut = 0x100,
.reg_volt_lut = 0x200,
+ .reg_intr_clr = 0x308,
.reg_perf_state = 0x320,
.lut_row_size = 4,
};
I believe this fix of a critical bug is intended to be included into the next
release, could you please share your review? Thank you in advance.
--
Best wishes,
Vladimir
