diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c
index 70c660121ec4..78f905bc6a42 100644
--- a/arch/powerpc/platforms/cell/spu_base.c
+++ b/arch/powerpc/platforms/cell/spu_base.c
@@ -219,15 +219,25 @@ static int __spu_trap_data_seg(struct spu *spu, unsigned long ea)
 extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap); //XXX
 static int __spu_trap_data_map(struct spu *spu, unsigned long ea, u64 dsisr)
 {
+	int ret;
+
 	pr_debug("%s, %lx, %lx\n", __func__, dsisr, ea);
 
-	/* Handle kernel space hash faults immediately.
-	   User hash faults need to be deferred to process context. */
-	if ((dsisr & MFC_DSISR_PTE_NOT_FOUND)
-	    && REGION_ID(ea) != USER_REGION_ID
-	    && hash_page(ea, _PAGE_PRESENT, 0x300) == 0) {
-		spu_restart_dma(spu);
-		return 0;
+	/*
+	 * Handle kernel space hash faults immediately. User hash
+	 * faults need to be deferred to process context.
+	 */
+	if ((dsisr & MFC_DSISR_PTE_NOT_FOUND) &&
+	    (REGION_ID(ea) != USER_REGION_ID)) {
+
+		spin_unlock(&spu->register_lock);
+		ret = hash_page(ea, _PAGE_PRESENT, 0x300);
+		spin_lock(&spu->register_lock);
+
+		if (!ret) {
+			spu_restart_dma(spu);
+			return 0;
+		}
 	}
 
 	spu->class_1_dar = ea;
@@ -324,17 +334,13 @@ spu_irq_class_0(int irq, void *data)
 	stat = spu_int_stat_get(spu, 0) & mask;
 
 	spu->class_0_pending |= stat;
-	spu->class_0_dsisr = spu_mfc_dsisr_get(spu);
 	spu->class_0_dar = spu_mfc_dar_get(spu);
-	spin_unlock(&spu->register_lock);
-
 	spu->stop_callback(spu, 0);
-
 	spu->class_0_pending = 0;
-	spu->class_0_dsisr = 0;
 	spu->class_0_dar = 0;
 
 	spu_int_stat_clear(spu, 0, stat);
+	spin_unlock(&spu->register_lock);
 
 	return IRQ_HANDLED;
 }
@@ -357,13 +363,12 @@ spu_irq_class_1(int irq, void *data)
 		spu_mfc_dsisr_set(spu, 0ul);
 	spu_int_stat_clear(spu, 1, stat);
 
-	if (stat & CLASS1_SEGMENT_FAULT_INTR)
-		__spu_trap_data_seg(spu, dar);
-
-	spin_unlock(&spu->register_lock);
 	pr_debug("%s: %lx %lx %lx %lx\n", __func__, mask, stat,
 			dar, dsisr);
 
+	if (stat & CLASS1_SEGMENT_FAULT_INTR)
+		__spu_trap_data_seg(spu, dar);
+
 	if (stat & CLASS1_STORAGE_FAULT_INTR)
 		__spu_trap_data_map(spu, dar, dsisr);
 
@@ -376,6 +381,8 @@ spu_irq_class_1(int irq, void *data)
 	spu->class_1_dsisr = 0;
 	spu->class_1_dar = 0;
 
+	spin_unlock(&spu->register_lock);
+
 	return stat ? IRQ_HANDLED : IRQ_NONE;
 }
 
@@ -394,14 +401,12 @@ spu_irq_class_2(int irq, void *data)
 	mask = spu_int_mask_get(spu, 2);
 	/* ignore interrupts we're not waiting for */
 	stat &= mask;
-
 	/* mailbox interrupts are level triggered. mask them now before
 	 * acknowledging */
 	if (stat & mailbox_intrs)
 		spu_int_mask_and(spu, 2, ~(stat & mailbox_intrs));
 	/* acknowledge all interrupts before the callbacks */
 	spu_int_stat_clear(spu, 2, stat);
-	spin_unlock(&spu->register_lock);
 
 	pr_debug("class 2 interrupt %d, %lx, %lx\n", irq, stat, mask);
 
@@ -421,6 +426,9 @@ spu_irq_class_2(int irq, void *data)
 		spu->wbox_callback(spu);
 
 	spu->stats.class2_intr++;
+
+	spin_unlock(&spu->register_lock);
+
 	return stat ? IRQ_HANDLED : IRQ_NONE;
 }
 
diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c
index b7493b865812..f7edba6cb795 100644
--- a/arch/powerpc/platforms/cell/spufs/run.c
+++ b/arch/powerpc/platforms/cell/spufs/run.c
@@ -27,7 +27,6 @@ void spufs_stop_callback(struct spu *spu, int irq)
 		switch(irq) {
 		case 0 :
 			ctx->csa.class_0_pending = spu->class_0_pending;
-			ctx->csa.class_0_dsisr = spu->class_0_dsisr;
 			ctx->csa.class_0_dar = spu->class_0_dar;
 			break;
 		case 1 :
@@ -51,18 +50,22 @@ int spu_stopped(struct spu_context *ctx, u32 *stat)
 	u64 dsisr;
 	u32 stopped;
 
-	*stat = ctx->ops->status_read(ctx);
-
-	if (test_bit(SPU_SCHED_NOTIFY_ACTIVE, &ctx->sched_flags))
-		return 1;
-
 	stopped = SPU_STATUS_INVALID_INSTR | SPU_STATUS_SINGLE_STEP |
 		SPU_STATUS_STOPPED_BY_HALT | SPU_STATUS_STOPPED_BY_STOP;
-	if (!(*stat & SPU_STATUS_RUNNING) && (*stat & stopped))
-		return 1;
 
-	dsisr = ctx->csa.class_0_dsisr;
-	if (dsisr & (MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED))
+top:
+	*stat = ctx->ops->status_read(ctx);
+	if (*stat & stopped) {
+		/*
+		 * If the spu hasn't finished stopping, we need to
+		 * re-read the register to get the stopped value.
+		 */
+		if (*stat & SPU_STATUS_RUNNING)
+			goto top;
+		return 1;
+	}
+
+	if (test_bit(SPU_SCHED_NOTIFY_ACTIVE, &ctx->sched_flags))
 		return 1;
 
 	dsisr = ctx->csa.class_1_dsisr;
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index 745dd51ec37f..e929e70a84e3 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -230,19 +230,23 @@ static void spu_bind_context(struct spu *spu, struct spu_context *ctx)
 	ctx->stats.slb_flt_base = spu->stats.slb_flt;
 	ctx->stats.class2_intr_base = spu->stats.class2_intr;
 
+	spu_associate_mm(spu, ctx->owner);
+
+	spin_lock_irq(&spu->register_lock);
 	spu->ctx = ctx;
 	spu->flags = 0;
 	ctx->spu = spu;
 	ctx->ops = &spu_hw_ops;
 	spu->pid = current->pid;
 	spu->tgid = current->tgid;
-	spu_associate_mm(spu, ctx->owner);
 	spu->ibox_callback = spufs_ibox_callback;
 	spu->wbox_callback = spufs_wbox_callback;
 	spu->stop_callback = spufs_stop_callback;
 	spu->mfc_callback = spufs_mfc_callback;
-	mb();
+	spin_unlock_irq(&spu->register_lock);
+
 	spu_unmap_mappings(ctx);
+
 	spu_switch_log_notify(spu, ctx, SWITCH_LOG_START, 0);
 	spu_restore(&ctx->csa, spu);
 	spu->timestamp = jiffies;
@@ -403,6 +407,8 @@ static int has_affinity(struct spu_context *ctx)
  */
 static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
 {
+	u32 status;
+
 	spu_context_trace(spu_unbind_context__enter, ctx, spu);
 
 	spuctx_switch_state(ctx, SPU_UTIL_SYSTEM);
@@ -423,18 +429,22 @@ static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
 	spu_unmap_mappings(ctx);
 	spu_save(&ctx->csa, spu);
 	spu_switch_log_notify(spu, ctx, SWITCH_LOG_STOP, 0);
+
+	spin_lock_irq(&spu->register_lock);
 	spu->timestamp = jiffies;
 	ctx->state = SPU_STATE_SAVED;
 	spu->ibox_callback = NULL;
 	spu->wbox_callback = NULL;
 	spu->stop_callback = NULL;
 	spu->mfc_callback = NULL;
-	spu_associate_mm(spu, NULL);
 	spu->pid = 0;
 	spu->tgid = 0;
 	ctx->ops = &spu_backing_ops;
 	spu->flags = 0;
 	spu->ctx = NULL;
+	spin_unlock_irq(&spu->register_lock);
+
+	spu_associate_mm(spu, NULL);
 
 	ctx->stats.slb_flt +=
 		(spu->stats.slb_flt - ctx->stats.slb_flt_base);
@@ -444,6 +454,9 @@ static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
 	/* This maps the underlying spu state to idle */
 	spuctx_switch_state(ctx, SPU_UTIL_IDLE_LOADED);
 	ctx->spu = NULL;
+
+	if (spu_stopped(ctx, &status))
+		wake_up_all(&ctx->stop_wq);
 }
 
 /**
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 1702de9395ee..bfcf70ee8959 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2844,7 +2844,6 @@ static void dump_spu_fields(struct spu *spu)
 	DUMP_FIELD(spu, "0x%lx", flags);
 	DUMP_FIELD(spu, "%d", class_0_pending);
 	DUMP_FIELD(spu, "0x%lx", class_0_dar);
-	DUMP_FIELD(spu, "0x%lx", class_0_dsisr);
 	DUMP_FIELD(spu, "0x%lx", class_1_dar);
 	DUMP_FIELD(spu, "0x%lx", class_1_dsisr);
 	DUMP_FIELD(spu, "0x%lx", irqs[0]);
diff --git a/include/asm-powerpc/spu.h b/include/asm-powerpc/spu.h
index 6abead6e681a..99348c1f4cab 100644
--- a/include/asm-powerpc/spu.h
+++ b/include/asm-powerpc/spu.h
@@ -131,7 +131,6 @@ struct spu {
 	u64 flags;
 	u64 class_0_pending;
 	u64 class_0_dar;
-	u64 class_0_dsisr;
 	u64 class_1_dar;
 	u64 class_1_dsisr;
 	size_t ls_size;
diff --git a/include/asm-powerpc/spu_csa.h b/include/asm-powerpc/spu_csa.h
index 129ec148d451..a40fd491250c 100644
--- a/include/asm-powerpc/spu_csa.h
+++ b/include/asm-powerpc/spu_csa.h
@@ -254,7 +254,7 @@ struct spu_state {
 	u64 spu_chnldata_RW[32];
 	u32 spu_mailbox_data[4];
 	u32 pu_mailbox_data[1];
-	u64 class_0_dar, class_0_dsisr, class_0_pending;
+	u64 class_0_dar, class_0_pending;
 	u64 class_1_dar, class_1_dsisr;
 	unsigned long suspend_time;
 	spinlock_t register_lock;