From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6CFDBC52D2B for ; Thu, 27 Feb 2020 14:00:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 41A2520578 for ; Thu, 27 Feb 2020 14:00:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582812006; bh=FKtU32cyw/UdGrE2fGzl7hamaEFms3FrtdtOUA6DtKo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=H9SBMoHfJOe20Q6f4Y/aQXcDujlpiLjLwQnlF8dr7/8lT5F/utmp/0Ofoly/+klz1 56qKOT6fPLsVKUY/l+YxBFBkL5/K9QGQznfTXap1kG4ur3gf8y972LkItPrJaJPbup sQclQvSUntF2dP5XFY/ww8J/uwWlLh3NhiAG3PBM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732681AbgB0OAE (ORCPT ); Thu, 27 Feb 2020 09:00:04 -0500 Received: from mail.kernel.org ([198.145.29.99]:33318 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732676AbgB0OAB (ORCPT ); Thu, 27 Feb 2020 09:00:01 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E454C2073D; Thu, 27 Feb 2020 13:59:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582812000; bh=FKtU32cyw/UdGrE2fGzl7hamaEFms3FrtdtOUA6DtKo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xdP4J7dKd2HjF1Lix3ukNpl25IH20L96nFh3W/LXuaI2IQNImQQdhcLFJkIn4vKF9 203pBoC9bdiL4QajLJKAwVdbgqaC9UBG1d6SrD8FWlrUKF+og6e6Kr6UlTJpgIn87P M0wATH469YSZCF3J9Mpledmk+aztHAXRev3lPGi8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Peter Chen , Mathias Nyman , Fabio Estevam Subject: [PATCH 4.14 182/237] usb: host: xhci: update event ring dequeue pointer on purpose Date: Thu, 27 Feb 2020 14:36:36 +0100 Message-Id: <20200227132309.751311272@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200227132255.285644406@linuxfoundation.org> References: <20200227132255.285644406@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Peter Chen commit dc0ffbea5729a3abafa577ebfce87f18b79e294b upstream. On some situations, the software handles TRB events slower than adding TRBs, then xhci_handle_event can't return zero long time, the xHC will consider the event ring is full, and trigger "Event Ring Full" error, but in fact, the software has already finished lots of events, just no chance to update ERDP (event ring dequeue pointer). In this commit, we force update ERDP if half of TRBS_PER_SEGMENT events have handled to avoid "Event Ring Full" error. Signed-off-by: Peter Chen Signed-off-by: Mathias Nyman Link: https://lore.kernel.org/r/1573836603-10871-2-git-send-email-mathias.nyman@linux.intel.com Signed-off-by: Fabio Estevam Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-ring.c | 60 ++++++++++++++++++++++++++++++------------- 1 file changed, 43 insertions(+), 17 deletions(-) --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -2759,6 +2759,42 @@ static int xhci_handle_event(struct xhci } /* + * Update Event Ring Dequeue Pointer: + * - When all events have finished + * - To avoid "Event Ring Full Error" condition + */ +static void xhci_update_erst_dequeue(struct xhci_hcd *xhci, + union xhci_trb *event_ring_deq) +{ + u64 temp_64; + dma_addr_t deq; + + temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue); + /* If necessary, update the HW's version of the event ring deq ptr. */ + if (event_ring_deq != xhci->event_ring->dequeue) { + deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg, + xhci->event_ring->dequeue); + if (deq == 0) + xhci_warn(xhci, "WARN something wrong with SW event ring dequeue ptr\n"); + /* + * Per 4.9.4, Software writes to the ERDP register shall + * always advance the Event Ring Dequeue Pointer value. + */ + if ((temp_64 & (u64) ~ERST_PTR_MASK) == + ((u64) deq & (u64) ~ERST_PTR_MASK)) + return; + + /* Update HC event ring dequeue pointer */ + temp_64 &= ERST_PTR_MASK; + temp_64 |= ((u64) deq & (u64) ~ERST_PTR_MASK); + } + + /* Clear the event handler busy flag (RW1C) */ + temp_64 |= ERST_EHB; + xhci_write_64(xhci, temp_64, &xhci->ir_set->erst_dequeue); +} + +/* * xHCI spec says we can get an interrupt, and if the HC has an error condition, * we might get bad data out of the event ring. Section 4.10.2.7 has a list of * indicators of an event TRB error, but we check the status *first* to be safe. @@ -2769,9 +2805,9 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd union xhci_trb *event_ring_deq; irqreturn_t ret = IRQ_NONE; unsigned long flags; - dma_addr_t deq; u64 temp_64; u32 status; + int event_loop = 0; spin_lock_irqsave(&xhci->lock, flags); /* Check if the xHC generated the interrupt, or the irq is shared */ @@ -2825,24 +2861,14 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd /* FIXME this should be a delayed service routine * that clears the EHB. */ - while (xhci_handle_event(xhci) > 0) {} - - temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue); - /* If necessary, update the HW's version of the event ring deq ptr. */ - if (event_ring_deq != xhci->event_ring->dequeue) { - deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg, - xhci->event_ring->dequeue); - if (deq == 0) - xhci_warn(xhci, "WARN something wrong with SW event " - "ring dequeue ptr.\n"); - /* Update HC event ring dequeue pointer */ - temp_64 &= ERST_PTR_MASK; - temp_64 |= ((u64) deq & (u64) ~ERST_PTR_MASK); + while (xhci_handle_event(xhci) > 0) { + if (event_loop++ < TRBS_PER_SEGMENT / 2) + continue; + xhci_update_erst_dequeue(xhci, event_ring_deq); + event_loop = 0; } - /* Clear the event handler busy flag (RW1C); event ring is empty. */ - temp_64 |= ERST_EHB; - xhci_write_64(xhci, temp_64, &xhci->ir_set->erst_dequeue); + xhci_update_erst_dequeue(xhci, event_ring_deq); ret = IRQ_HANDLED; out: