Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934169Ab1FWSGz (ORCPT ); Thu, 23 Jun 2011 14:06:55 -0400 Received: from mail.windriver.com ([147.11.1.11]:34690 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933447Ab1FWRgy (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 134/247] xhci: Clarify some expressions in the TRB math Date: Thu, 23 Jun 2011 13:33:22 -0400 Message-Id: <1308850515-15242-75-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: 5042 Lines: 114 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 a2490187011cc2263117626615a581927d19f1d3 upstream. This makes it easier to spot some problems, which will be fixed by the next patch in the series. Also change dev_dbg to dev_err in check_trb_math(), so any math errors will be visible even when running with debug disabled. Note: This patch changes the expressions containing "((1 << TRB_MAX_BUFF_SHIFT) - 1)" to use the equivalent "(TRB_MAX_BUFF_SIZE - 1)". No change in behavior is intended for those expressions. This patch should be queued for stable kernels back to 2.6.31. [PG: 34 doesn't have count_isoc_trbs_needed() hence this has one less instance to change vs. the originating release] Signed-off-by: Paul Zimmerman Signed-off-by: Sarah Sharp Signed-off-by: Paul Gortmaker --- drivers/usb/host/xhci-ring.c | 19 +++++++++---------- 1 files changed, 9 insertions(+), 10 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 6ead609..8bf5563 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1710,7 +1710,7 @@ static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb) /* Scatter gather list entries may cross 64KB boundaries */ running_total = TRB_MAX_BUFF_SIZE - - (sg_dma_address(sg) & ((1 << TRB_MAX_BUFF_SHIFT) - 1)); + (sg_dma_address(sg) & (TRB_MAX_BUFF_SIZE - 1)); if (running_total != 0) num_trbs++; @@ -1740,11 +1740,11 @@ static unsigned int count_sg_trbs_needed(struct xhci_hcd *xhci, struct urb *urb) static void check_trb_math(struct urb *urb, int num_trbs, int running_total) { if (num_trbs != 0) - dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated number of " + dev_err(&urb->dev->dev, "%s - ep %#x - Miscalculated number of " "TRBs, %d left\n", __func__, urb->ep->desc.bEndpointAddress, num_trbs); if (running_total != urb->transfer_buffer_length) - dev_dbg(&urb->dev->dev, "%s - ep %#x - Miscalculated tx length, " + dev_err(&urb->dev->dev, "%s - ep %#x - Miscalculated tx length, " "queued %#x (%d), asked for %#x (%d)\n", __func__, urb->ep->desc.bEndpointAddress, @@ -1866,8 +1866,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, sg = urb->sg->sg; addr = (u64) sg_dma_address(sg); this_sg_len = sg_dma_len(sg); - trb_buff_len = TRB_MAX_BUFF_SIZE - - (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1)); + trb_buff_len = TRB_MAX_BUFF_SIZE - (addr & (TRB_MAX_BUFF_SIZE - 1)); trb_buff_len = min_t(int, trb_buff_len, this_sg_len); if (trb_buff_len > urb->transfer_buffer_length) trb_buff_len = urb->transfer_buffer_length; @@ -1903,7 +1902,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, (unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1), (unsigned int) addr + trb_buff_len); if (TRB_MAX_BUFF_SIZE - - (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1)) < trb_buff_len) { + (addr & (TRB_MAX_BUFF_SIZE - 1)) < trb_buff_len) { xhci_warn(xhci, "WARN: sg dma xfer crosses 64KB boundaries!\n"); xhci_dbg(xhci, "Next boundary at %#x, end dma = %#x\n", (unsigned int) (addr + TRB_MAX_BUFF_SIZE) & ~(TRB_MAX_BUFF_SIZE - 1), @@ -1943,7 +1942,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, } trb_buff_len = TRB_MAX_BUFF_SIZE - - (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1)); + (addr & (TRB_MAX_BUFF_SIZE - 1)); trb_buff_len = min_t(int, trb_buff_len, this_sg_len); if (running_total + trb_buff_len > urb->transfer_buffer_length) trb_buff_len = @@ -1978,7 +1977,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, num_trbs = 0; /* How much data is (potentially) left before the 64KB boundary? */ running_total = TRB_MAX_BUFF_SIZE - - (urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1)); + (urb->transfer_dma & (TRB_MAX_BUFF_SIZE - 1)); /* If there's some data on this 64KB chunk, or we have to send a * zero-length transfer, we need at least one TRB @@ -2017,8 +2016,8 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, /* How much data is in the first TRB? */ addr = (u64) urb->transfer_dma; trb_buff_len = TRB_MAX_BUFF_SIZE - - (urb->transfer_dma & ((1 << TRB_MAX_BUFF_SHIFT) - 1)); - if (urb->transfer_buffer_length < trb_buff_len) + (urb->transfer_dma & (TRB_MAX_BUFF_SIZE - 1)); + if (trb_buff_len > urb->transfer_buffer_length) trb_buff_len = urb->transfer_buffer_length; first_trb = true; -- 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/