Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752442AbbF2Agu (ORCPT ); Sun, 28 Jun 2015 20:36:50 -0400 Received: from mail-pd0-f174.google.com ([209.85.192.174]:34276 "EHLO mail-pd0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752767AbbF2Agm (ORCPT ); Sun, 28 Jun 2015 20:36:42 -0400 From: Reyad Attiyat To: gregkh@linuxfoundation.org, mathias.nyman@intel.com Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, Reyad Attiyat Subject: [PATCH] usb: xhci: Add support for URB_ZERO_PACKET to bulk/sg transfers Date: Sun, 28 Jun 2015 19:36:38 -0500 Message-Id: <1435538198-3509-1-git-send-email-reyad.attiyat@gmail.com> X-Mailer: git-send-email 2.4.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4738 Lines: 133 This commit checks for the URB_ZERO_PACKET flag and creates an extra zero-length td if the urb transfer length is a multiple of the endpoint max packet length. Signed-off-by: Reyad Attiyat --- drivers/usb/host/xhci-ring.c | 41 ++++++++++++++++++++++++++++++++--------- 1 file changed, 32 insertions(+), 9 deletions(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 7d34cbf..fb24099 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -3040,7 +3040,9 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, int num_sgs; int trb_buff_len, this_sg_len, running_total; unsigned int total_packet_count; + bool zero_length_needed; bool first_trb; + int last_trb; u64 addr; bool more_trbs_coming; @@ -3056,6 +3058,14 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, total_packet_count = DIV_ROUND_UP(urb->transfer_buffer_length, usb_endpoint_maxp(&urb->ep->desc)); + /* Deal with URB_ZERO_PACKET - need one more td/trb */ + zero_length_needed = (urb->transfer_flags & URB_ZERO_PACKET) + && !(urb->transfer_buffer_length % usb_endpoint_maxp(&urb->ep->desc)); + if(zero_length_needed){ + num_trbs++; + xhci_dbg(xhci, "Creating zero length td.\n"); + } + trb_buff_len = prepare_transfer(xhci, xhci->devs[slot_id], ep_index, urb->stream_id, num_trbs, urb, 0, mem_flags); @@ -3092,6 +3102,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, trb_buff_len = urb->transfer_buffer_length; first_trb = true; + last_trb = zero_length_needed ? 2 : 1; /* Queue the first TRB, even if it's zero-length */ do { u32 field = 0; @@ -3109,12 +3120,13 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags, /* Chain all the TRBs together; clear the chain bit in the last * TRB to indicate it's the last TRB in the chain. */ - if (num_trbs > 1) { + if (num_trbs > last_trb) { field |= TRB_CHAIN; - } else { - /* FIXME - add check for ZERO_PACKET flag before this */ + } else if (num_trbs == last_trb) { td->last_trb = ep_ring->enqueue; field |= TRB_IOC; + } else if (zero_length_needed && num_trbs == 1) { + trb_buff_len = 0; } /* Only set interrupt on short packet for IN endpoints */ @@ -3194,7 +3206,9 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, int num_trbs; struct xhci_generic_trb *start_trb; bool first_trb; + int last_trb; bool more_trbs_coming; + bool zero_length_needed; int start_cycle; u32 field, length_field; @@ -3225,7 +3239,14 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, num_trbs++; running_total += TRB_MAX_BUFF_SIZE; } - /* FIXME: this doesn't deal with URB_ZERO_PACKET - need one more */ + + /* Deal with URB_ZERO_PACKET - need one more td/trb */ + zero_length_needed = (urb->transfer_flags & URB_ZERO_PACKET) + && !(urb->transfer_buffer_length % usb_endpoint_maxp(&urb->ep->desc)); + if(zero_length_needed){ + num_trbs++; + xhci_dbg(xhci, "Creating zero length td.\n"); + } ret = prepare_transfer(xhci, xhci->devs[slot_id], ep_index, urb->stream_id, @@ -3255,7 +3276,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, trb_buff_len = urb->transfer_buffer_length; first_trb = true; - + last_trb = zero_length_needed ? 2 : 1; /* Queue the first TRB, even if it's zero-length */ do { u32 remainder = 0; @@ -3272,12 +3293,14 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, /* Chain all the TRBs together; clear the chain bit in the last * TRB to indicate it's the last TRB in the chain. */ - if (num_trbs > 1) { + + if (num_trbs > last_trb) { field |= TRB_CHAIN; - } else { - /* FIXME - add check for ZERO_PACKET flag before this */ + } else if (num_trbs == last_trb) { td->last_trb = ep_ring->enqueue; field |= TRB_IOC; + } else if (zero_length_needed && num_trbs == 1) { + trb_buff_len = 0; } /* Only set interrupt on short packet for IN endpoints */ @@ -3315,7 +3338,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags, trb_buff_len = urb->transfer_buffer_length - running_total; if (trb_buff_len > TRB_MAX_BUFF_SIZE) trb_buff_len = TRB_MAX_BUFF_SIZE; - } while (running_total < urb->transfer_buffer_length); + } while (num_trbs > 0); check_trb_math(urb, num_trbs, running_total); giveback_first_trb(xhci, slot_id, ep_index, urb->stream_id, -- 2.4.3 -- 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/