Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934179Ab1FWSG4 (ORCPT ); Thu, 23 Jun 2011 14:06:56 -0400 Received: from mail.windriver.com ([147.11.1.11]:34687 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933443Ab1FWRgy (ORCPT ); Thu, 23 Jun 2011 13:36:54 -0400 From: Paul Gortmaker To: stable@kernel.org, linux-kernel@vger.kernel.org Cc: stable-review@kernel.org, Paul Zimmerman , Paul Zimmerman , Sarah Sharp , Paul Gortmaker Subject: [34-longterm 136/247] xhci: Fix an error in count_sg_trbs_needed() Date: Thu, 23 Jun 2011 13:33:24 -0400 Message-Id: <1308850515-15242-77-git-send-email-paul.gortmaker@windriver.com> X-Mailer: git-send-email 1.7.4.4 In-Reply-To: <1308850515-15242-1-git-send-email-paul.gortmaker@windriver.com> References: <1308849690-14530-1-git-send-email-paul.gortmaker@windriver.com> <1308850515-15242-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1817 Lines: 52 From: Paul Zimmerman ------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. ------------------- commit bcd2fde05341cef0052e49566ec88b406a521cf3 upstream. The expression while (running_total < sg_dma_len(sg)) does not take into account that the remaining data length can be less than sg_dma_len(sg). In that case, running_total can end up being greater than the total data length, so an extra TRB is counted. Changing the expression to while (running_total < sg_dma_len(sg) && running_total < temp) fixes that. This patch should be queued for stable kernels back to 2.6.31. Signed-off-by: Paul Zimmerman Signed-off-by: Sarah Sharp Signed-off-by: Paul Gortmaker --- drivers/usb/host/xhci-ring.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index e4afa99..34ce5d4 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1716,7 +1716,7 @@ static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb) num_trbs++; /* How many more 64KB chunks to transfer, how many more TRBs? */ - while (running_total < sg_dma_len(sg)) { + while (running_total < sg_dma_len(sg) && running_total < temp) { num_trbs++; running_total += TRB_MAX_BUFF_SIZE; } -- 1.7.4.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/