Instead of erroring out when GuC reset is in progress, block waiting for GuC reset to complete which is a more reasonable uapi behavior. v2: Avoid race between wake_up_all and waiting for wakeup (Rodrigo) Signed-off-by: Ashutosh Dixit <ashutosh.dixit@xxxxxxxxx> --- drivers/gpu/drm/i915/i915_hwmon.c | 38 +++++++++++++++++++++++++++---- 1 file changed, 33 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_hwmon.c b/drivers/gpu/drm/i915/i915_hwmon.c index 9ab8971679fe3..8471a667dfc71 100644 --- a/drivers/gpu/drm/i915/i915_hwmon.c +++ b/drivers/gpu/drm/i915/i915_hwmon.c @@ -51,6 +51,7 @@ struct hwm_drvdata { char name[12]; int gt_n; bool reset_in_progress; + wait_queue_head_t waitq; }; struct i915_hwmon { @@ -395,16 +396,41 @@ hwm_power_max_read(struct hwm_drvdata *ddat, long *val) static int hwm_power_max_write(struct hwm_drvdata *ddat, long val) { +#define GUC_RESET_TIMEOUT msecs_to_jiffies(2000) + + int ret = 0, timeout = GUC_RESET_TIMEOUT; struct i915_hwmon *hwmon = ddat->hwmon; intel_wakeref_t wakeref; - int ret = 0; + DEFINE_WAIT(wait); u32 nval; - mutex_lock(&hwmon->hwmon_lock); - if (hwmon->ddat.reset_in_progress) { - ret = -EAGAIN; - goto unlock; + /* Block waiting for GuC reset to complete when needed */ + for (;;) { + mutex_lock(&hwmon->hwmon_lock); + + prepare_to_wait(&ddat->waitq, &wait, TASK_INTERRUPTIBLE); + + if (!hwmon->ddat.reset_in_progress) + break; + + if (signal_pending(current)) { + ret = -EINTR; + break; + } + + if (!timeout) { + ret = -ETIME; + break; + } + + mutex_unlock(&hwmon->hwmon_lock); + + timeout = schedule_timeout(timeout); } + finish_wait(&ddat->waitq, &wait); + if (ret) + goto unlock; + wakeref = intel_runtime_pm_get(ddat->uncore->rpm); /* Disable PL1 limit and verify, because the limit cannot be disabled on all platforms */ @@ -508,6 +534,7 @@ void i915_hwmon_power_max_restore(struct drm_i915_private *i915, bool old) intel_uncore_rmw(hwmon->ddat.uncore, hwmon->rg.pkg_rapl_limit, PKG_PWR_LIM_1_EN, old ? PKG_PWR_LIM_1_EN : 0); hwmon->ddat.reset_in_progress = false; + wake_up_all(&hwmon->ddat.waitq); mutex_unlock(&hwmon->hwmon_lock); } @@ -784,6 +811,7 @@ void i915_hwmon_register(struct drm_i915_private *i915) ddat->uncore = &i915->uncore; snprintf(ddat->name, sizeof(ddat->name), "i915"); ddat->gt_n = -1; + init_waitqueue_head(&ddat->waitq); for_each_gt(gt, i915, i) { ddat_gt = hwmon->ddat_gt + i; -- 2.38.0