msm: kgsl: Allow the wait_timeout to be disabled

With the improved hang detection we don't technically need a upper
timeout bound for a process to wait in waitfortimestamp().  Allow
for a idle_timestamp of '0' to allow the loop to wait for ever.
The infrastructure for changing the idle_timeout still exists
so it can be changed to whatever value is appropriate for debugging
or testing.

CRs-fixed: 382366
CRs-fixed: 383999
Change-Id: Ic0dedbadf2c100eb56ed2338914575061776e725
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
diff --git a/drivers/gpu/msm/adreno_ringbuffer.c b/drivers/gpu/msm/adreno_ringbuffer.c
index e0ef1fd..ad9007f 100644
--- a/drivers/gpu/msm/adreno_ringbuffer.c
+++ b/drivers/gpu/msm/adreno_ringbuffer.c
@@ -52,11 +52,9 @@
 	unsigned int freecmds;
 	unsigned int *cmds;
 	uint cmds_gpu;
-	struct adreno_device *adreno_dev = ADRENO_DEVICE(rb->device);
-	unsigned long wait_timeout = msecs_to_jiffies(adreno_dev->wait_timeout);
 	unsigned long wait_time;
+	unsigned long wait_timeout = msecs_to_jiffies(ADRENO_IDLE_TIMEOUT);
 	unsigned long wait_time_part;
-	unsigned int msecs_part = KGSL_TIMEOUT_PART;
 	unsigned int prev_reg_val[hang_detect_regs_count];
 
 	memset(prev_reg_val, 0, sizeof(prev_reg_val));
@@ -87,7 +85,7 @@
 	}
 
 	wait_time = jiffies + wait_timeout;
-	wait_time_part = jiffies + msecs_to_jiffies(msecs_part);
+	wait_time_part = jiffies + msecs_to_jiffies(KGSL_TIMEOUT_PART);
 	/* wait for space in ringbuffer */
 	while (1) {
 		GSL_RB_GET_READPTR(rb, &rb->rptr);
@@ -101,7 +99,7 @@
 		 */
 		if (time_after(jiffies, wait_time_part)) {
 			wait_time_part = jiffies +
-				msecs_to_jiffies(msecs_part);
+				msecs_to_jiffies(KGSL_TIMEOUT_PART);
 			if ((adreno_hang_detect(rb->device,
 						prev_reg_val))){
 				KGSL_DRV_ERR(rb->device,