From 579e33549dc2293bf16b5571483bac2d36567318 Mon Sep 17 00:00:00 2001
From: Rob Clark <robdclark@gmail.com>
Date: Mon, 31 Aug 2015 13:31:15 -0400
Subject: WIP: synchronize gralloc entry points

Note entirely sure what synchronization guarantees android provides
before calling in to module.. but stuff inside gralloc module is
definately not thread-safe so slap a big lock around the outside.
---
 gralloc.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 55 insertions(+), 15 deletions(-)

diff --git a/gralloc.c b/gralloc.c
index 92866ca..b338ab9 100644
--- a/gralloc.c
+++ b/gralloc.c
@@ -32,6 +32,8 @@
 #include "gralloc_drm.h"
 #include "gralloc_drm_priv.h"
 
+static pthread_mutex_t gralloc_lock = PTHREAD_MUTEX_INITIALIZER;
+
 /*
  * Initialize the DRM device object, optionally with KMS.
  */
@@ -114,13 +116,23 @@ static int drm_mod_register_buffer(const gralloc_module_t *mod,
 	if (err)
 		return err;
 
-	return gralloc_drm_handle_register(handle, dmod->drm);
+	pthread_mutex_lock(&gralloc_lock);
+	err = gralloc_drm_handle_register(handle, dmod->drm);
+	pthread_mutex_unlock(&gralloc_lock);
+
+	return err;
 }
 
 static int drm_mod_unregister_buffer(const gralloc_module_t *mod,
 		buffer_handle_t handle)
 {
-	return gralloc_drm_handle_unregister(handle);
+	int err;
+
+	pthread_mutex_lock(&gralloc_lock);
+	err = gralloc_drm_handle_unregister(handle);
+	pthread_mutex_unlock(&gralloc_lock);
+
+	return err;
 }
 
 static int drm_mod_lock(const gralloc_module_t *mod, buffer_handle_t handle,
@@ -129,25 +141,40 @@ static int drm_mod_lock(const gralloc_module_t *mod, buffer_handle_t handle,
 	struct gralloc_drm_bo_t *bo;
 	int err;
 
+	pthread_mutex_lock(&gralloc_lock);
+
 	bo = gralloc_drm_bo_from_handle(handle);
-	if (!bo)
-		return -EINVAL;
+	if (!bo) {
+		err = -EINVAL;
+		goto unlock;
+	}
 
-	return gralloc_drm_bo_lock(bo, usage, x, y, w, h, ptr);
+	err = gralloc_drm_bo_lock(bo, usage, x, y, w, h, ptr);
+
+unlock:
+	pthread_mutex_unlock(&gralloc_lock);
+	return err;
 }
 
 static int drm_mod_unlock(const gralloc_module_t *mod, buffer_handle_t handle)
 {
 	struct drm_module_t *dmod = (struct drm_module_t *) mod;
 	struct gralloc_drm_bo_t *bo;
+	int err = 0;
+
+	pthread_mutex_lock(&gralloc_lock);
 
 	bo = gralloc_drm_bo_from_handle(handle);
-	if (!bo)
-		return -EINVAL;
+	if (!bo) {
+		err = -EINVAL;
+		goto unlock;
+	}
 
 	gralloc_drm_bo_unlock(bo);
 
-	return 0;
+unlock:
+	pthread_mutex_unlock(&gralloc_lock);
+	return err;
 }
 
 static int drm_mod_close_gpu0(struct hw_device_t *dev)
@@ -163,14 +190,21 @@ static int drm_mod_free_gpu0(alloc_device_t *dev, buffer_handle_t handle)
 {
 	struct drm_module_t *dmod = (struct drm_module_t *) dev->common.module;
 	struct gralloc_drm_bo_t *bo;
+	int err = 0;
+
+	pthread_mutex_lock(&gralloc_lock);
 
 	bo = gralloc_drm_bo_from_handle(handle);
-	if (!bo)
-		return -EINVAL;
+	if (!bo) {
+		err = -EINVAL;
+		goto unlock;
+	}
 
 	gralloc_drm_bo_decref(bo);
 
-	return 0;
+unlock:
+	pthread_mutex_unlock(&gralloc_lock);
+	return err;
 }
 
 static int drm_mod_alloc_gpu0(alloc_device_t *dev,
@@ -179,15 +213,19 @@ static int drm_mod_alloc_gpu0(alloc_device_t *dev,
 {
 	struct drm_module_t *dmod = (struct drm_module_t *) dev->common.module;
 	struct gralloc_drm_bo_t *bo;
-	int size, bpp, err;
+	int size, bpp, err = 0;
 
 	bpp = gralloc_drm_get_bpp(format);
 	if (!bpp)
 		return -EINVAL;
 
+	pthread_mutex_lock(&gralloc_lock);
+
 	bo = gralloc_drm_bo_create(dmod->drm, w, h, format, usage);
-	if (!bo)
-		return -ENOMEM;
+	if (!bo) {
+		err = -ENOMEM;
+		goto unlock;
+	}
 
 	if (gralloc_drm_bo_need_fb(bo)) {
 		err = gralloc_drm_bo_add_fb(bo);
@@ -202,7 +240,9 @@ static int drm_mod_alloc_gpu0(alloc_device_t *dev,
 	/* in pixels */
 	*stride /= bpp;
 
-	return 0;
+unlock:
+	pthread_mutex_unlock(&gralloc_lock);
+	return err;
 }
 
 static int drm_mod_open_gpu0(struct drm_module_t *dmod, hw_device_t **dev)
-- 
cgit v1.1