Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756069AbaBTXyJ (ORCPT ); Thu, 20 Feb 2014 18:54:09 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:46264 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756047AbaBTXyE (ORCPT ); Thu, 20 Feb 2014 18:54:04 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sarah Sharp Subject: [PATCH 3.13 77/99] Revert "usb: xhci: Link TRB must not occur within a USB payload burst" Date: Thu, 20 Feb 2014 15:53:12 -0800 Message-Id: <20140220235120.435346701@linuxfoundation.org> X-Mailer: git-send-email 1.9.0 In-Reply-To: <20140220235118.191692546@linuxfoundation.org> References: <20140220235118.191692546@linuxfoundation.org> User-Agent: quilt/0.61-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sarah Sharp commit 3d4b81eda2211f32886e2978daf6f39885042fc4 upstream. This reverts commit 35773dac5f862cb1c82ea151eba3e2f6de51ec3e. It's a hack that caused regressions in the usb-storage and userspace USB drivers that use usbfs and libusb. Commit 70cabb7d992f "xhci 1.0: Limit arbitrarily-aligned scatter gather." should fix the issues seen with the ax88179_178a driver on xHCI 1.0 hosts, without causing regressions. Signed-off-by: Sarah Sharp Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-ring.c | 54 +------------------------------------------ include/linux/usb.h | 2 - 2 files changed, 2 insertions(+), 54 deletions(-) --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2973,58 +2973,8 @@ static int prepare_ring(struct xhci_hcd } while (1) { - if (room_on_ring(xhci, ep_ring, num_trbs)) { - union xhci_trb *trb = ep_ring->enqueue; - unsigned int usable = ep_ring->enq_seg->trbs + - TRBS_PER_SEGMENT - 1 - trb; - u32 nop_cmd; - - /* - * Section 4.11.7.1 TD Fragments states that a link - * TRB must only occur at the boundary between - * data bursts (eg 512 bytes for 480M). - * While it is possible to split a large fragment - * we don't know the size yet. - * Simplest solution is to fill the trb before the - * LINK with nop commands. - */ - if (num_trbs == 1 || num_trbs <= usable || usable == 0) - break; - - if (ep_ring->type != TYPE_BULK) - /* - * While isoc transfers might have a buffer that - * crosses a 64k boundary it is unlikely. - * Since we can't add NOPs without generating - * gaps in the traffic just hope it never - * happens at the end of the ring. - * This could be fixed by writing a LINK TRB - * instead of the first NOP - however the - * TRB_TYPE_LINK_LE32() calls would all need - * changing to check the ring length. - */ - break; - - if (num_trbs >= TRBS_PER_SEGMENT) { - xhci_err(xhci, "Too many fragments %d, max %d\n", - num_trbs, TRBS_PER_SEGMENT - 1); - return -ENOMEM; - } - - nop_cmd = cpu_to_le32(TRB_TYPE(TRB_TR_NOOP) | - ep_ring->cycle_state); - ep_ring->num_trbs_free -= usable; - do { - trb->generic.field[0] = 0; - trb->generic.field[1] = 0; - trb->generic.field[2] = 0; - trb->generic.field[3] = nop_cmd; - trb++; - } while (--usable); - ep_ring->enqueue = trb; - if (room_on_ring(xhci, ep_ring, num_trbs)) - break; - } + if (room_on_ring(xhci, ep_ring, num_trbs)) + break; if (ep_ring == xhci->cmd_ring) { xhci_err(xhci, "Do not support expand command ring\n"); --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -1264,8 +1264,6 @@ typedef void (*usb_complete_t)(struct ur * @sg: scatter gather buffer list, the buffer size of each element in * the list (except the last) must be divisible by the endpoint's * max packet size if no_sg_constraint isn't set in 'struct usb_bus' - * (FIXME: scatter-gather under xHCI is broken for periodic transfers. - * Do not use urb->sg for interrupt endpoints for now, only bulk.) * @num_mapped_sgs: (internal) number of mapped sg entries * @num_sgs: number of entries in the sg list * @transfer_buffer_length: How big is transfer_buffer. The transfer may -- 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/