From patchwork Thu Sep 13 12:24:02 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathias Nyman X-Patchwork-Id: 10599431 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id D138014BD for ; Thu, 13 Sep 2018 12:21:09 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C23E62A9A8 for ; Thu, 13 Sep 2018 12:21:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B6CA32AB2C; Thu, 13 Sep 2018 12:21:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4AA0C2AAE6 for ; Thu, 13 Sep 2018 12:21:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727838AbeIMRaW (ORCPT ); Thu, 13 Sep 2018 13:30:22 -0400 Received: from mga18.intel.com ([134.134.136.126]:17657 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727365AbeIMRaV (ORCPT ); Thu, 13 Sep 2018 13:30:21 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Sep 2018 05:21:08 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,369,1531810800"; d="scan'208";a="88427556" Received: from mattu-haswell.fi.intel.com ([10.237.72.164]) by fmsmga004.fm.intel.com with ESMTP; 13 Sep 2018 05:21:07 -0700 From: Mathias Nyman To: Cc: , Mathias Nyman Subject: [PATCH 09/10] xhci: Use soft retry to recover faster from transaction errors Date: Thu, 13 Sep 2018 15:24:02 +0300 Message-Id: <1536841443-10713-10-git-send-email-mathias.nyman@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1536841443-10713-1-git-send-email-mathias.nyman@linux.intel.com> References: <1536841443-10713-1-git-send-email-mathias.nyman@linux.intel.com> Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Use soft retry to recover from a USB Transaction Errors that are caused by temporary error conditions. The USB device is not aware that the xHC has halted the endpoint, and will be waiting for another retry A Soft Retry perform additional retries and recover from an error which has caused the xHC to halt an endpoint. Soft retry has some limitations: Soft Retry attempts shall not be performed on Isoch endpoints Soft Retry attempts shall not be performed if the device is behind a TT in a HS Hub Software shall limit the number of unsuccessful Soft Retry attempts to prevent an infinite loop. For more details on Soft retry see xhci specs 4.6.8.1 Signed-off-by: Mathias Nyman --- drivers/usb/host/xhci-ring.c | 19 +++++++++++++++++++ drivers/usb/host/xhci.h | 2 ++ 2 files changed, 21 insertions(+) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index f0a99aa..c41341e 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -1155,6 +1155,10 @@ static void xhci_handle_cmd_reset_ep(struct xhci_hcd *xhci, int slot_id, /* Clear our internal halted state */ xhci->devs[slot_id]->eps[ep_index].ep_state &= ~EP_HALTED; } + + /* if this was a soft reset, then restart */ + if ((le32_to_cpu(trb->generic.field[3])) & TRB_TSP) + ring_doorbell_for_active_rings(xhci, slot_id, ep_index); } static void xhci_handle_cmd_enable_slot(struct xhci_hcd *xhci, int slot_id, @@ -2132,10 +2136,16 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td, union xhci_trb *ep_trb, struct xhci_transfer_event *event, struct xhci_virt_ep *ep, int *status) { + struct xhci_slot_ctx *slot_ctx; struct xhci_ring *ep_ring; u32 trb_comp_code; u32 remaining, requested, ep_trb_len; + unsigned int slot_id; + int ep_index; + slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags)); + slot_ctx = xhci_get_slot_ctx(xhci, xhci->devs[slot_id]->out_ctx); + ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1; ep_ring = xhci_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer)); trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len)); remaining = EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)); @@ -2144,6 +2154,7 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td, switch (trb_comp_code) { case COMP_SUCCESS: + ep_ring->err_count = 0; /* handle success with untransferred data as short packet */ if (ep_trb != td->last_trb || remaining) { xhci_warn(xhci, "WARN Successful completion on short TX\n"); @@ -2167,6 +2178,14 @@ static int process_bulk_intr_td(struct xhci_hcd *xhci, struct xhci_td *td, ep_trb_len = 0; remaining = 0; break; + case COMP_USB_TRANSACTION_ERROR: + if ((ep_ring->err_count++ > MAX_SOFT_RETRY) || + le32_to_cpu(slot_ctx->tt_info) & TT_SLOT) + break; + *status = 0; + xhci_cleanup_halted_endpoint(xhci, slot_id, ep_index, + ep_ring->stream_id, td, EP_SOFT_RESET); + return 0; default: /* do nothing */ break; diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 6230a57..b635785 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1496,6 +1496,7 @@ static inline const char *xhci_trb_type_string(u8 type) /* How much data is left before the 64KB boundary? */ #define TRB_BUFF_LEN_UP_TO_BOUNDARY(addr) (TRB_MAX_BUFF_SIZE - \ (addr & (TRB_MAX_BUFF_SIZE - 1))) +#define MAX_SOFT_RETRY 3 struct xhci_segment { union xhci_trb *trbs; @@ -1583,6 +1584,7 @@ struct xhci_ring { * if we own the TRB (if we are the consumer). See section 4.9.1. */ u32 cycle_state; + unsigned int err_count; unsigned int stream_id; unsigned int num_segs; unsigned int num_trbs_free;