diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
index 857f3f11258aa..ef232c0c20493 100644
--- a/drivers/gpu/drm/panthor/panthor_fw.c
+++ b/drivers/gpu/drm/panthor/panthor_fw.c
@@ -1089,6 +1089,12 @@ int panthor_fw_post_reset(struct panthor_device *ptdev)
 		panthor_fw_stop(ptdev);
 		ptdev->fw->fast_reset = false;
 		drm_err(&ptdev->base, "FW fast reset failed, trying a slow reset");
+
+		ret = panthor_vm_flush_all(ptdev->fw->vm);
+		if (ret) {
+			drm_err(&ptdev->base, "FW slow reset failed (couldn't flush FW's AS l2cache)");
+			return ret;
+		}
 	}
 
 	/* Reload all sections, including RO ones. We're not supposed
@@ -1099,7 +1105,7 @@ int panthor_fw_post_reset(struct panthor_device *ptdev)
 
 	ret = panthor_fw_start(ptdev);
 	if (ret) {
-		drm_err(&ptdev->base, "FW slow reset failed");
+		drm_err(&ptdev->base, "FW slow reset failed (couldn't start the FW )");
 		return ret;
 	}
 
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
index 15be29ff46c39..4f0f9cf6426b6 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -873,14 +873,27 @@ static int panthor_vm_flush_range(struct panthor_vm *vm, u64 iova, u64 size)
 	if (!drm_dev_enter(&ptdev->base, &cookie))
 		return 0;
 
-	/* Flush the PTs only if we're already awake */
-	if (pm_runtime_active(ptdev->base.dev))
-		ret = mmu_hw_do_operation(vm, iova, size, AS_COMMAND_FLUSH_PT);
+	/*
+	 * If we made it this far, that means the device is awake, because
+	 * upon device suspension, all active VMs are given an AS id of -1
+	 */
+	ret = mmu_hw_do_operation(vm, iova, size, AS_COMMAND_FLUSH_PT);
 
 	drm_dev_exit(cookie);
 	return ret;
 }
 
+/**
+ * panthor_vm_flush_all() - Flush L2 caches for the entirety of a VM's AS
+ * @vm: VM whose cache to flush
+ *
+ * Return: 0 on success, a negative error code if flush failed.
+ */
+int panthor_vm_flush_all(struct panthor_vm *vm)
+{
+	return panthor_vm_flush_range(vm, vm->base.mm_start, vm->base.mm_range);
+}
+
 static int panthor_vm_unmap_pages(struct panthor_vm *vm, u64 iova, u64 size)
 {
 	struct panthor_device *ptdev = vm->ptdev;
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.h b/drivers/gpu/drm/panthor/panthor_mmu.h
index e6a2198b009b7..10635cc8a94df 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.h
+++ b/drivers/gpu/drm/panthor/panthor_mmu.h
@@ -31,6 +31,7 @@ panthor_vm_get_bo_for_va(struct panthor_vm *vm, u64 va, u64 *bo_offset);
 int panthor_vm_active(struct panthor_vm *vm);
 void panthor_vm_idle(struct panthor_vm *vm);
 int panthor_vm_as(struct panthor_vm *vm);
+int panthor_vm_flush_all(struct panthor_vm *vm);
 
 struct panthor_heap_pool *
 panthor_vm_get_heap_pool(struct panthor_vm *vm, bool create);