From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754525Ab2L1T4U (ORCPT ); Fri, 28 Dec 2012 14:56:20 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:54982 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754345Ab2L1TRJ (ORCPT ); Fri, 28 Dec 2012 14:17:09 -0500 Message-Id: <20121228190401.136910932@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Fri, 28 Dec 2012 20:06:09 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Johannes Berg , Shuah Khan , Emmanuel Grumbach Subject: [ 159/173] iwlwifi: handle DMA mapping failures In-Reply-To: <20121228190330.025298996@decadent.org.uk> X-SA-Exim-Connect-IP: 151.217.219.220 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg commit 7c34158231b2eda8dcbd297be2bb1559e69cb433 upstream. 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"). Reported-by: Shuah Khan Reviewed-by: Emmanuel Grumbach Signed-off-by: Johannes Berg [bwh: Backported to 3.2: - Adjust filename, context, indentation - Use bus(trans) instead of trans where necessary - Use hw_params(trans).rx_page_order instead of trans_pcie->rx_page_order] Signed-off-by: Ben Hutchings --- drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) --- a/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c +++ b/drivers/net/wireless/iwlwifi/iwl-trans-pcie-rx.c @@ -311,6 +311,14 @@ static void iwlagn_rx_allocate(struct iw rxb->page_dma = dma_map_page(bus(trans)->dev, page, 0, PAGE_SIZE << hw_params(trans).rx_page_order, DMA_FROM_DEVICE); + if (dma_mapping_error(bus(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, hw_params(trans).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! */ @@ -489,8 +497,19 @@ static void iwl_rx_handle(struct iwl_tra 0, PAGE_SIZE << hw_params(trans).rx_page_order, DMA_FROM_DEVICE); - list_add_tail(&rxb->list, &rxq->rx_free); - rxq->free_count++; + if (dma_mapping_error(bus(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, hw_params(trans).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);