ttm: Fix spelling mistakes and remove unused #ifdef

. and some comments to make it easier to understand.

Ackedby: Randy Dunlap <[e-mail]>
[v2: Added some more updates from Randy Dunlap]
Signed-off-by: Konrad Rzeszutek Wilk <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/ttm/ttm_page_alloc.c

···
 			if (nr_free)
 				goto restart;
 
-			/* Not allowed to fall tough or break because
+			/* Not allowed to fall through or break because
 			 * following context is inside spinlock while we are
 			 * outside here.
 			 */
···
 }
 
 /**
- * Fill the given pool if there isn't enough pages and requested number of
+ * Fill the given pool if there aren't enough pages and the requested number of
  * pages is small.
  */
 static void ttm_page_pool_fill_locked(struct ttm_page_pool *pool,
···
 
 	pool->fill_lock = true;
 
-	/* If allocation request is small and there is not enough
-	 * pages in pool we fill the pool first */
+	/* If allocation request is small and there are not enough
+	 * pages in a pool we fill the pool up first. */
 	if (count < _manager->options.small
 		&& count > pool->npages) {
 		struct list_head new_pages;
···
 }
 
 /**
- * Cut count nubmer of pages from the pool and put them to return list
+ * Cut 'count' number of pages from the pool and put them on the return list.
  *
- * @return count of pages still to allocate to fill the request.
+ * @return count of pages still required to fulfill the request.
  */
 static unsigned ttm_page_pool_get_pages(struct ttm_page_pool *pool,
 		struct list_head *pages, int ttm_flags,
···
 		goto out;
 	}
 	/* find the last pages to include for requested number of pages. Split
-	 * pool to begin and halves to reduce search space. */
+	 * pool to begin and halve it to reduce search space. */
 	if (count <= pool->npages/2) {
 		i = 0;
 		list_for_each(p, &pool->list) {
···
 				break;
 		}
 	}
-	/* Cut count number of pages from pool */
+	/* Cut 'count' number of pages from the pool */
 	list_cut_position(pages, &pool->list, p);
 	pool->npages -= count;
 	count = 0;

include/drm/ttm/ttm_bo_api.h

···
 
 extern void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
 
-#if 0
-#endif
-
 /**
  * ttm_fbdev_mmap - mmap fbdev memory backed by a ttm buffer object.
  *

include/drm/ttm/ttm_bo_driver.h

···
 	 *
 	 * Bind the backend pages into the aperture in the location
 	 * indicated by @bo_mem. This function should be able to handle
-	 * differences between aperture- and system page sizes.
+	 * differences between aperture and system page sizes.
 	 */
 	int (*bind) (struct ttm_backend *backend, struct ttm_mem_reg *bo_mem);
 
···
 	 * @backend: Pointer to a struct ttm_backend.
 	 *
 	 * Unbind previously bound backend pages. This function should be
-	 * able to handle differences between aperture- and system page sizes.
+	 * able to handle differences between aperture and system page sizes.
 	 */
 	int (*unbind) (struct ttm_backend *backend);
 
···
  * ttm_bo_device_init
  *
  * @bdev: A pointer to a struct ttm_bo_device to initialize.
- * @mem_global: A pointer to an initialized struct ttm_mem_global.
+ * @glob: A pointer to an initialized struct ttm_bo_global.
  * @driver: A pointer to a struct ttm_bo_driver set up by the caller.
  * @file_page_offset: Offset into the device address space that is available
  * for buffer data. This ensures compatibility with other users of the

include/drm/ttm/ttm_memory.h

···
  * @do_shrink: The callback function.
  *
  * Arguments to the do_shrink functions are intended to be passed using
- * inheritance. That is, the argument class derives from struct ttm_mem_srink,
+ * inheritance. That is, the argument class derives from struct ttm_mem_shrink,
  * and can be accessed using container_of().
  */
 

include/drm/ttm/ttm_object.h

···
  *
  * @ref_obj_release: A function to be called when a reference object
  * with another ttm_ref_type than TTM_REF_USAGE is deleted.
- * this function may, for example, release a lock held by a user-space
+ * This function may, for example, release a lock held by a user-space
  * process.
  *
  * This struct is intended to be used as a base struct for objects that
···
 /**
  * ttm_base_object_unref
  *
- * @p_base: Pointer to a pointer referncing a struct ttm_base_object.
+ * @p_base: Pointer to a pointer referencing a struct ttm_base_object.
  *
  * Decrements the base object refcount and clears the pointer pointed to by
  * p_base.

include/drm/ttm/ttm_page_alloc.h

···
 /**
  * Get count number of pages from pool to pages list.
  *
- * @pages: heado of empty linked list where pages are filled.
+ * @pages: head of empty linked list where pages are filled.
  * @flags: ttm flags for page allocation.
  * @cstate: ttm caching state for the page.
  * @count: number of pages to allocate.