From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760701Ab1CEBOS (ORCPT ); Fri, 4 Mar 2011 20:14:18 -0500 Received: from kroah.org ([198.145.64.141]:50247 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760371Ab1CEBAQ (ORCPT ); Fri, 4 Mar 2011 20:00:16 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Fri Mar 4 16:56:37 2011 Message-Id: <20110305005637.511201005@clark.kroah.org> User-Agent: quilt/0.48-11.2 Date: Fri, 04 Mar 2011 16:55:35 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Paul Zimmerman , Sarah Sharp Subject: [30/73] xhci: Clarify some expressions in the TRB math In-Reply-To: <20110305005720.GA16162@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.37-stable review patch. If anyone has any objections, please let us know. ------------------ From: Paul Zimmerman 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. Signed-off-by: Paul Zimmerman Signed-off-by: Sarah Sharp Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-ring.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2374,7 +2374,7 @@ static unsigned int count_sg_trbs_needed /* 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++; @@ -2404,11 +2404,11 @@ static unsigned int count_sg_trbs_needed 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, @@ -2540,8 +2540,7 @@ static int queue_bulk_sg_tx(struct xhci_ sg = urb->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; @@ -2577,7 +2576,7 @@ static int queue_bulk_sg_tx(struct xhci_ (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), @@ -2621,7 +2620,7 @@ static int queue_bulk_sg_tx(struct xhci_ } 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 = @@ -2661,7 +2660,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd * 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 @@ -2704,8 +2703,8 @@ int xhci_queue_bulk_tx(struct xhci_hcd * /* 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; @@ -2877,8 +2876,7 @@ static int count_isoc_trbs_needed(struct addr = (u64) (urb->transfer_dma + urb->iso_frame_desc[i].offset); td_len = urb->iso_frame_desc[i].length; - running_total = TRB_MAX_BUFF_SIZE - - (addr & ((1 << TRB_MAX_BUFF_SHIFT) - 1)); + running_total = TRB_MAX_BUFF_SIZE - (addr & (TRB_MAX_BUFF_SIZE - 1)); if (running_total != 0) num_trbs++;