From: Imre Deak <imre.deak@nokia.com>
Date: Mon, 5 Apr 2010 20:18:24 +0000 (+0300)
Subject: gpu: pvr: fix locking on the DVFS path
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c9fb404c8192e6e5b35a77d65d092214e5d5ce5b;p=sgx.git

gpu: pvr: fix locking on the DVFS path

The HW state is protected by pvr_lock(), so acquire it for the
duration of clock rate changes. We can also remove PVRSRVDvfsLock()
that thus becomes unneded.

Signed-off-by: Imre Deak <imre.deak@nokia.com>
CC: Mark Underwood <mark.underwood@imgtec.com>
CC: Mark Riding <mark.riding@imgtec.com>
Reviewed-by: Topi Pohjolainen <topi.pohjolainen@nokia.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@nokia.com>
---

diff --git a/pvr/power.c b/pvr/power.c
index 35adf6a..17afd51 100644
--- a/pvr/power.c
+++ b/pvr/power.c
@@ -34,8 +34,6 @@ static IMG_BOOL gbInitServerRunning;
 static IMG_BOOL gbInitServerRan;
 static IMG_BOOL gbInitSuccessful;
 static DEFINE_MUTEX(hPowerAndFreqLock);
-static DECLARE_WAIT_QUEUE_HEAD(hDvfsWq);
-static IMG_BOOL gbDvfsActive;
 
 enum PVRSRV_ERROR PVRSRVSetInitServerState(enum PVRSRV_INIT_SERVER_STATE
 					  eInitServerState, IMG_BOOL bState)
@@ -91,42 +89,15 @@ static IMG_BOOL _IsSystemStatePowered(enum PVR_POWER_STATE eSystemPowerState)
 	return (IMG_BOOL)(eSystemPowerState < PVRSRV_POWER_STATE_D2);
 }
 
-void PVRSRVDvfsLock(void)
-{
-	mutex_lock(&hPowerAndFreqLock);
-	gbDvfsActive = 1;
-	mutex_unlock(&hPowerAndFreqLock);
-}
-
-void PVRSRVDvfsUnlock(void)
-{
-	mutex_lock(&hPowerAndFreqLock);
-	gbDvfsActive = 0;
-	wake_up(&hDvfsWq);
-	mutex_unlock(&hPowerAndFreqLock);
-}
-
 enum PVRSRV_ERROR PVRSRVPowerLock(u32 ui32CallerID, IMG_BOOL bSystemPowerEvent)
 {
 	if (ui32CallerID == TIMER_ID) {
 		if (!mutex_trylock(&hPowerAndFreqLock))
 			return PVRSRV_ERROR_RETRY;
-
-		if (gbDvfsActive) {
-			mutex_unlock(&hPowerAndFreqLock);
-			return PVRSRV_ERROR_RETRY;
-		}
-	} else
+	} else {
 		mutex_lock(&hPowerAndFreqLock);
-
-	while (gbDvfsActive) {
-		DEFINE_WAIT(__wait);
-		prepare_to_wait(&hDvfsWq, &__wait, TASK_UNINTERRUPTIBLE);
-		mutex_unlock(&hPowerAndFreqLock);
-		schedule();
-		mutex_lock(&hPowerAndFreqLock);
-		finish_wait(&hDvfsWq, &__wait);
 	}
+
 	return PVRSRV_OK;
 }
 
diff --git a/pvr/power.h b/pvr/power.h
index 807f167..3ea861e 100644
--- a/pvr/power.h
+++ b/pvr/power.h
@@ -63,8 +63,6 @@ enum PVRSRV_ERROR PVRSRVSetInitServerState(enum PVRSRV_INIT_SERVER_STATE
 enum PVRSRV_ERROR PVRSRVPowerLock(u32 ui32CallerID,
 		IMG_BOOL bSystemPowerEvent);
 void PVRSRVPowerUnlock(u32 ui32CallerID);
-void PVRSRVDvfsLock(void);
-void PVRSRVDvfsUnlock(void);
 
 enum PVRSRV_ERROR PVRSRVSetDevicePowerStateKM(u32 ui32DeviceIndex,
 		enum PVR_POWER_STATE eNewPowerState, u32 ui32CallerID,
diff --git a/pvr/sysutils.c b/pvr/sysutils.c
index 6aa8ac1..874692d 100644
--- a/pvr/sysutils.c
+++ b/pvr/sysutils.c
@@ -144,16 +144,16 @@ static int vdd2_pre_post_func(struct notifier_block *n, unsigned long event,
 		  cnd->rate);
 
 	if (CLK_PRE_RATE_CHANGE == event) {
-		PVRSRVDvfsLock();
+		pvr_lock();
 		PVR_TRACE("vdd2_pre_post_func: CLK_PRE_RATE_CHANGE event");
 		vdd2_pre_func(n, event, ptr);
 	} else if (CLK_POST_RATE_CHANGE == event) {
 		PVR_TRACE("vdd2_pre_post_func: CLK_POST_RATE_CHANGE event");
 		vdd2_post_func(n, event, ptr);
-		PVRSRVDvfsUnlock();
+		pvr_unlock();
 	} else if (CLK_ABORT_RATE_CHANGE == event) {
 		PVR_TRACE("vdd2_pre_post_func: CLK_ABORT_RATE_CHANGE event");
-		PVRSRVDvfsUnlock();
+		pvr_unlock();
 	} else {
 		printk(KERN_ERR "vdd2_pre_post_func: unexpected event (%lu)\n",
 			event);