msm: kgsl: GPU fault tolerance timer

GPU fault tolerance timer with a 50ms interval is introduced to detect
the condition where GPU is stalled, when GPU state is active we check
for GPU stall and if a stall is detected fault tolerance is triggered.
Using a timer is a better design because this removes dependency
on userspace to call waittimestamp.

Conflicts:

    drivers/gpu/msm/adreno.c
    drivers/gpu/msm/kgsl_pwrctrl.c

CRs-Fixed: 477979
Change-Id: I22b1316ad3edb271c1241b93e7a36373dfc70234
Signed-off-by: Tarun Karra <tkarra@codeaurora.org>
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>
diff --git a/drivers/gpu/msm/kgsl_pwrctrl.c b/drivers/gpu/msm/kgsl_pwrctrl.c
index a9cda0a..26cc96c 100644
--- a/drivers/gpu/msm/kgsl_pwrctrl.c
+++ b/drivers/gpu/msm/kgsl_pwrctrl.c
@@ -1106,6 +1106,7 @@
 			kgsl_pwrctrl_request_state(device, KGSL_STATE_NONE);
 			return -EBUSY;
 		}
+		del_timer_sync(&device->hang_timer);
 		kgsl_pwrctrl_irq(device, KGSL_PWRFLAGS_OFF);
 		kgsl_pwrctrl_clk(device, KGSL_PWRFLAGS_OFF, KGSL_STATE_NAP);
 		kgsl_pwrctrl_set_state(device, KGSL_STATE_NAP);
@@ -1175,6 +1176,7 @@
 	case KGSL_STATE_NAP:
 	case KGSL_STATE_SLEEP:
 		del_timer_sync(&device->idle_timer);
+		del_timer_sync(&device->hang_timer);
 		/* make sure power is on to stop the device*/
 		kgsl_pwrctrl_enable(device);
 		device->ftbl->suspend_context(device);
@@ -1269,6 +1271,8 @@
 		/* Re-enable HW access */
 		mod_timer(&device->idle_timer,
 				jiffies + device->pwrctrl.interval_timeout);
+		mod_timer(&device->hang_timer,
+			(jiffies + msecs_to_jiffies(KGSL_TIMEOUT_PART)));
 		pm_qos_update_request(&device->pm_qos_req_dma,
 					GPU_SWFI_LATENCY);
 	case KGSL_STATE_ACTIVE: