[AGPGART] Add some debugging printk's. Based on Linus' earlier patch.

drivers/char/agp/frontend.c

@@ -40,6 +40,14 @@
 #include <asm/pgtable.h>
 #include "agp.h"
 
+//#define DEBUG
+
+#ifdef DEBUG
+#define DBG(x,y...) printk (KERN_DEBUG "agpgart: %s: " x "\n", __FUNCTION__ , ## y)
+#else
+#define DBG(x,y...) do { } while (0)
+#endif
+
 static struct agp_front_data agp_fe;
 
 static agp_memory *agp_find_mem_by_key(int key)
@@ -53,11 +61,12 @@ static agp_memory *agp_find_mem_by_key(int key)
 
 	while (curr != NULL) {
 		if (curr->key == key)
-			return curr;
+			break;
 		curr = curr->next;
 	}
 
-	return NULL;
+	DBG("key=%d -> mem=%p", key, curr);
+	return curr;
 }
 
 static void agp_remove_from_pool(agp_memory * temp)
@@ -67,6 +76,7 @@ static void agp_remove_from_pool(agp_memory * temp)
 
 	/* Check to see if this is even in the memory pool */
 
+	DBG("mem=%p", temp);
 	if (agp_find_mem_by_key(temp->key) != NULL) {
 		next = temp->next;
 		prev = temp->prev;
@@ -119,10 +129,16 @@ static agp_segment_priv *agp_find_seg_in_client(const agp_client * client,
 
 static void agp_remove_seg_from_client(agp_client * client)
 {
+	DBG("client=%p", client);
+
 	if (client->segments != NULL) {
-		if (*(client->segments) != NULL)
+		if (*(client->segments) != NULL) {
+			DBG("Freeing %p from client", *(client->segments), client);
 			kfree(*(client->segments));
+		}
+		DBG("Freeing %p from client %p", client->segments, client);
 		kfree(client->segments);
+		client->segments = NULL;
 	}
 }
 
@@ -136,6 +152,7 @@ static void agp_add_seg_to_client(agp_client * client,
 	if (prev_seg != NULL)
 		agp_remove_seg_from_client(client);
 
+	DBG("Adding seg %p (%d segments) to client %p", seg, num_segments, client);
 	client->num_segments = num_segments;
 	client->segments = seg;
 }
@@ -599,6 +616,7 @@ static int agp_mmap(struct file *file, struct vm_area_struct *vma)
 	current_size = kerninfo.aper_size;
 	current_size = current_size * 0x100000;
 	offset = vma->vm_pgoff << PAGE_SHIFT;
+	DBG("%lx:%lx", offset, offset+size);
 
 	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
 		if ((size + offset) > current_size)
@@ -612,6 +630,7 @@ static int agp_mmap(struct file *file, struct vm_area_struct *vma)
 		if (!agp_find_seg_in_client(client, offset, size, vma->vm_page_prot))
 			goto out_inval;
 
+		DBG("client vm_ops=%p", kerninfo.vm_ops);
 		if (kerninfo.vm_ops) {
 			vma->vm_ops = kerninfo.vm_ops;
 		} else if (remap_page_range(vma, vma->vm_start, 
@@ -627,6 +646,7 @@ static int agp_mmap(struct file *file, struct vm_area_struct *vma)
 		if (size != current_size)
 			goto out_inval;
 
+		DBG("controller vm_ops=%p", kerninfo.vm_ops);
 		if (kerninfo.vm_ops) {
 			vma->vm_ops = kerninfo.vm_ops;
 		} else if (remap_page_range(vma, vma->vm_start, 
@@ -657,6 +677,8 @@ static int agp_release(struct inode *inode, struct file *file)
 
 	down(&(agp_fe.agp_mutex));
 
+	DBG("priv=%p", priv);
+
 	if (test_bit(AGP_FF_IS_CONTROLLER, &priv->access_flags)) {
 		agp_controller *controller;
 
@@ -670,9 +692,10 @@ static int agp_release(struct inode *inode, struct file *file)
 			agp_remove_controller(controller);
 		}
 	}
-	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags)) {
+
+	if (test_bit(AGP_FF_IS_CLIENT, &priv->access_flags))
 		agp_remove_client(priv->my_pid);
-	}
+
 	agp_remove_file_private(priv);
 	kfree(priv);
 	up(&(agp_fe.agp_mutex));
@@ -711,6 +734,7 @@ static int agp_open(struct inode *inode, struct file *file)
 	}
 	file->private_data = (void *) priv;
 	agp_insert_file_private(priv);
+	DBG("private=%p, client=%p", priv, client);
 	up(&(agp_fe.agp_mutex));
 	return 0;
 
@@ -760,8 +784,10 @@ static int agpioc_info_wrap(agp_file_private * priv, unsigned long arg)
 static int agpioc_acquire_wrap(agp_file_private * priv, unsigned long arg)
 {
 	int ret;
-
 	agp_controller *controller;
+
+	DBG("");
+
 	if (!(test_bit(AGP_FF_ALLOW_CONTROLLER, &priv->access_flags)))
 		return -EPERM;
 
@@ -797,6 +823,7 @@ static int agpioc_acquire_wrap(agp_file_private * priv, unsigned long arg)
 
 static int agpioc_release_wrap(agp_file_private * priv, unsigned long arg)
 {
+	DBG("");
 	agp_controller_release_current(agp_fe.current_controller, priv);
 	return 0;
 }
@@ -805,9 +832,10 @@ static int agpioc_setup_wrap(agp_file_private * priv, unsigned long arg)
 {
 	agp_setup mode;
 
-	if (copy_from_user(&mode, (void *) arg, sizeof(agp_setup))) {
+	DBG("");
+	if (copy_from_user(&mode, (void *) arg, sizeof(agp_setup)))
 		return -EFAULT;
-	}
+
 	agp_enable(mode.agp_mode);
 	return 0;
 }
@@ -818,6 +846,7 @@ static int agpioc_reserve_wrap(agp_file_private * priv, unsigned long arg)
 	agp_client *client;
 	agp_file_private *client_priv;
 
+	DBG("");
 	if (copy_from_user(&reserve, (void *) arg, sizeof(agp_region)))
 		return -EFAULT;
 
@@ -887,6 +916,7 @@ static int agpioc_reserve_wrap(agp_file_private * priv, unsigned long arg)
 
 static int agpioc_protect_wrap(agp_file_private * priv, unsigned long arg)
 {
+	DBG("");
 	/* This function is not currently implemented */
 	return -EINVAL;
 }
@@ -896,6 +926,7 @@ static int agpioc_allocate_wrap(agp_file_private * priv, unsigned long arg)
 	agp_memory *memory;
 	agp_allocate alloc;
 
+	DBG("");
 	if (copy_from_user(&alloc, (void *) arg, sizeof(agp_allocate)))
 		return -EFAULT;
 
@@ -918,6 +949,7 @@ static int agpioc_deallocate_wrap(agp_file_private * priv, unsigned long arg)
 {
 	agp_memory *memory;
 
+	DBG("");
 	memory = agp_find_mem_by_key((int) arg);
 
 	if (memory == NULL)
@@ -932,6 +964,7 @@ static int agpioc_bind_wrap(agp_file_private * priv, unsigned long arg)
 	agp_bind bind_info;
 	agp_memory *memory;
 
+	DBG("");
 	if (copy_from_user(&bind_info, (void *) arg, sizeof(agp_bind)))
 		return -EFAULT;
 
@@ -948,6 +981,7 @@ static int agpioc_unbind_wrap(agp_file_private * priv, unsigned long arg)
 	agp_memory *memory;
 	agp_unbind unbind;
 
+	DBG("");
 	if (copy_from_user(&unbind, (void *) arg, sizeof(agp_unbind)))
 		return -EFAULT;
 
@@ -965,6 +999,7 @@ static int agp_ioctl(struct inode *inode, struct file *file,
 	agp_file_private *curr_priv = (agp_file_private *) file->private_data;
 	int ret_val = -ENOTTY;
 
+	DBG("priv=%p, cmd=%x", curr_priv, cmd);
 	down(&(agp_fe.agp_mutex));
 
 	if ((agp_fe.current_controller == NULL) &&
@@ -1034,6 +1069,7 @@ static int agp_ioctl(struct inode *inode, struct file *file,
 	}
 
 ioctl_out:
+	DBG("ioctl returns %d\n", ret_val);
 	up(&(agp_fe.agp_mutex));
 	return ret_val;
 }