SLPC min/max frequency updates require H2G calls. We are seeing
timeouts when GuC channel is backed up and it is unable to respond
in a timely fashion causing warnings and affecting CI.
This is seen when waitboosting happens during a stress test.
this patch updates the waitboost path to use a non-blocking
H2G call instead, which returns as soon as the message is
successfully transmitted.
v2: Use drm_notice to report any errors that might occur while
sending the waitboost H2G request (Tvrtko)
v3: Add drm_notice inside force_min_freq (Ashutosh)
Cc: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx>
Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@xxxxxxxxx>
---
drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c | 42 +++++++++++++++++----
1 file changed, 35 insertions(+), 7 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
index 2df31af70d63..ec9c4ca0f615 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_slpc.c
@@ -98,6 +98,30 @@ static u32 slpc_get_state(struct intel_guc_slpc *slpc)
return data->header.global_state;
}
+static int guc_action_slpc_set_param_nb(struct intel_guc *guc, u8 id, u32 value)
+{
+ u32 request[] = {
+ GUC_ACTION_HOST2GUC_PC_SLPC_REQUEST,
+ SLPC_EVENT(SLPC_EVENT_PARAMETER_SET, 2),
+ id,
+ value,
+ };
+ int ret;
+
+ ret = intel_guc_send_nb(guc, request, ARRAY_SIZE(request), 0);
+
+ return ret > 0 ? -EPROTO : ret;
+}
+
+static int slpc_set_param_nb(struct intel_guc_slpc *slpc, u8 id, u32 value)
+{
+ struct intel_guc *guc = slpc_to_guc(slpc);
+
+ GEM_BUG_ON(id >= SLPC_MAX_PARAM);
+
+ return guc_action_slpc_set_param_nb(guc, id, value);
+}
+
static int guc_action_slpc_set_param(struct intel_guc *guc, u8 id, u32 value)
{
u32 request[] = {
@@ -208,12 +232,14 @@ static int slpc_force_min_freq(struct intel_guc_slpc *slpc, u32 freq)
*/
with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
- ret = slpc_set_param(slpc,
- SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ,
- freq);
+ /* Non-blocking request will avoid stalls */
+ ret = slpc_set_param_nb(slpc,
+ SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ,
+ freq);
if (ret)
- i915_probe_error(i915, "Unable to force min freq to %u: %d",
- freq, ret);
+ drm_notice(&i915->drm,
+ "Failed to send set_param for min freq(%d): (%d)\n",
+ freq, ret);
}
return ret;
@@ -222,6 +248,7 @@ static int slpc_force_min_freq(struct intel_guc_slpc *slpc, u32 freq)
static void slpc_boost_work(struct work_struct *work)
{
struct intel_guc_slpc *slpc = container_of(work, typeof(*slpc), boost_work);
+ int err;
/*
* Raise min freq to boost. It's possible that
@@ -231,8 +258,9 @@ static void slpc_boost_work(struct work_struct *work)
*/
mutex_lock(&slpc->lock);
if (atomic_read(&slpc->num_waiters)) {
- slpc_force_min_freq(slpc, slpc->boost_freq);
- slpc->num_boosts++;
+ err = slpc_force_min_freq(slpc, slpc->boost_freq);
+ if (!err)
+ slpc->num_boosts++;
}
mutex_unlock(&slpc->lock);
}
--
2.35.1
