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Commit 7c341582 authored by Johannes Berg's avatar Johannes Berg
Browse files

iwlwifi: handle DMA mapping failures 



The RX replenish code doesn't handle DMA mapping failures,
which will cause issues if there actually is a failure. This
was reported by Shuah Khan who found a DMA mapping framework
warning ("device driver failed to check map error").

Cc: stable@vger.kernel.org
Reported-by: default avatarShuah Khan <shuah.khan@hp.com>
Reviewed-by: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 8f7b8db6

drivers/net/wireless/iwlwifi/pcie/rx.c

+21 −2
Original line number Diff line number Diff line
@@ -321,6 +321,14 @@ static void iwl_rx_allocate(struct iwl_trans *trans, gfp_t priority) 
			dma_map_page(trans->dev, page, 0,

				     PAGE_SIZE << trans_pcie->rx_page_order,

				     DMA_FROM_DEVICE);

		if (dma_mapping_error(trans->dev, rxb->page_dma)) {

			rxb->page = NULL;

			spin_lock_irqsave(&rxq->lock, flags);

			list_add(&rxb->list, &rxq->rx_used);

			spin_unlock_irqrestore(&rxq->lock, flags);

			__free_pages(page, trans_pcie->rx_page_order);

			return;

		}

		/* dma address must be no more than 36 bits */

		BUG_ON(rxb->page_dma & ~DMA_BIT_MASK(36));

		/* and also 256 byte aligned! */
@@ -488,8 +496,19 @@ static void iwl_rx_handle_rxbuf(struct iwl_trans *trans, 
			dma_map_page(trans->dev, rxb->page, 0,

				     PAGE_SIZE << trans_pcie->rx_page_order,

				     DMA_FROM_DEVICE);

		if (dma_mapping_error(trans->dev, rxb->page_dma)) {

			/*

			 * free the page(s) as well to not break

			 * the invariant that the items on the used

			 * list have no page(s)

			 */

			__free_pages(rxb->page, trans_pcie->rx_page_order);

			rxb->page = NULL;

			list_add_tail(&rxb->list, &rxq->rx_used);

		} else {

			list_add_tail(&rxb->list, &rxq->rx_free);

			rxq->free_count++;

		}

	} else

		list_add_tail(&rxb->list, &rxq->rx_used);

	spin_unlock_irqrestore(&rxq->lock, flags);