Re: [PATCH 10/14] drm/ttm: provide dma aware ttm page pool code V8

+int ttm_dma_populate(struct ttm_tt *ttm, struct device *dev) +{

.. snip..

• for (i = 0; i < ttm->num_pages; ++i) {

• ret = ttm_dma_pool_get_pages(pool, ttm, i);
  

• if (ret != 0) {
  

• 	ttm_dma_unpopulate(ttm, dev);
  

• 	return -ENOMEM;
  

• }
  

• ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
  

• 				false, false);
  

Ok, so we increment it here..

.. snip..

+void ttm_dma_unpopulate(struct ttm_tt *ttm, struct device *dev) +{

• struct dma_pool *pool;
• struct dma_page *d_page;
• enum pool_type type;
• bool is_cached = false;
• unsigned count = 0, i;
• unsigned long irq_flags;
• type = ttm_to_type(ttm->page_flags, ttm->caching_state);
• pool = ttm_dma_find_pool(dev, type);
• if (!pool) {

• WARN_ON(!pool);
  

• return;
  

• }
• is_cached = (ttm_dma_find_pool(pool->dev,

•      ttm_to_type(ttm->page_flags, tt_cached)) == pool);
  

• /* make sure pages array match list and count number of pages */
• list_for_each_entry(d_page, &ttm->alloc_list, page_list) {

• ttm->pages[count] = d_page->p;
  

• count++;
  

• }
• spin_lock_irqsave(&pool->lock, irq_flags);
• pool->npages_in_use -= count;
• if (is_cached) {

• pool->nfrees += count;
  

• } else {

• pool->npages_free += count;
  

• list_splice(&ttm->alloc_list, &pool->free_list);
  

• if (pool->npages_free > _manager->options.max_size) {
  

• 	count = pool->npages_free - _manager->options.max_size;
  

• }
  

• }
• spin_unlock_irqrestore(&pool->lock, irq_flags);

But we don't do it here. I think you need:

for (i = 0; i < ttm->num_pages; i++) { ttm_mem_global_free_page(mem_glob, ttm->pages[i]);

And it has to be done before ttm_dma_pages_put as at that point the pages are truly gone.

Could actually be done in the '/* make sure pages array match list .."

• if (is_cached) {

• ttm_dma_pages_put(pool, &ttm->alloc_list,
  

• 		  ttm->pages, count);
  

• }
• INIT_LIST_HEAD(&ttm->alloc_list);
• for (i = 0; i < ttm->num_pages; i++) {

• ttm->pages[i] = NULL;
  

• ttm->dma_address[i] = 0;
  

• }