commit 9d099a1b868f0a9c6a13db171f63dd26a97b3f44
author Super Liu <supercjliu@google.com> Tue Sep 19 00:38:03 2023 +0000
committer Super Liu <supercjliu@google.com> Wed Sep 20 06:00:17 2023 +0000
tree 421efce6a1e69f9e59067e8a308495aa6ca0fa96
parent 7f921e8d6bf3a03e8d731fda839a5eb8ea4cc54b

gti: fix the race between irq and pm

In the context of the TDDI project, the vendor driver
will handle wake-up gestures without requiring a prior
request for an IRQ wakelock. This situation may potentially
lead to a race condition of input_process() between the
release_all_fingers() and the irq_thread_fn(). The changes
is to keep IRQ wakelock logic to avoid the race between.

Bug: 298137746
Test: verify wake-up gesture.
Test: keeps persistent fingers to reproduce issue along
      with suspend and resume.
Change-Id: I358f386fe6a428b07158c09f447dcab030ea9127
Signed-off-by: Super Liu <supercjliu@google.com>

goog_touch_interface.c

diff --git a/goog_touch_interface.c b/goog_touch_interface.c
index dc8ac24..a966060 100644
--- a/goog_touch_interface.c
+++ b/goog_touch_interface.c
@@ -3471,20 +3471,22 @@
 
 static irqreturn_t gti_irq_thread_fn(int irq, void *data)
 {
-	int error;
+	int pm_ret;
 	irqreturn_t ret = IRQ_NONE;
 	struct goog_touch_interface *gti = (struct goog_touch_interface *)data;
 
 	ATRACE_BEGIN(__func__);
-
-	if (gti->tbn_enabled) {
-		error = goog_pm_wake_lock(gti, GTI_PM_WAKELOCK_TYPE_IRQ, true);
-		if (error < 0) {
-			GOOG_WARN(gti, "Skipping stray interrupt, pm state: (%d, %d)\n",
-					gti->pm.state, gti->pm.new_state);
-			ATRACE_END();
-			return IRQ_HANDLED;
-		}
+	/*
+	 * Allow vendor driver to handle wake-up gesture events by irq_thread_fn()
+	 * after pm_suspend() complete without requiring a prior request for an IRQ
+	 * wakelock. This is only for the tbn_enabled disabled case.
+	 */
+	pm_ret = goog_pm_wake_lock(gti, GTI_PM_WAKELOCK_TYPE_IRQ, true);
+	if (pm_ret < 0 && gti->tbn_enabled) {
+		GOOG_WARN(gti, "Skipping stray interrupt, pm state: (%d, %d)\n",
+				gti->pm.state, gti->pm.new_state);
+		ATRACE_END();
+		return IRQ_HANDLED;
 	}
 
 	cpu_latency_qos_update_request(&gti->pm_qos_req, 100 /* usec */);
@@ -3507,7 +3509,7 @@
 
 	gti_debug_hc_update(gti, false);
 	cpu_latency_qos_update_request(&gti->pm_qos_req, PM_QOS_DEFAULT_VALUE);
-	if (gti->tbn_enabled)
+	if (pm_ret == 0)
 		goog_pm_wake_unlock_nosync(gti, GTI_PM_WAKELOCK_TYPE_IRQ);
 	ATRACE_END();