From patchwork Wed Aug 19 05:17:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 11722521 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8BD8413A4 for ; Wed, 19 Aug 2020 05:17:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 68AFC2078B for ; Wed, 19 Aug 2020 05:17:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=mg.codeaurora.org header.i=@mg.codeaurora.org header.b="IWiUBtUI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725804AbgHSFRs (ORCPT ); Wed, 19 Aug 2020 01:17:48 -0400 Received: from m43-7.mailgun.net ([69.72.43.7]:57491 "EHLO m43-7.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725306AbgHSFRq (ORCPT ); Wed, 19 Aug 2020 01:17:46 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1597814265; h=Content-Transfer-Encoding: MIME-Version: Message-Id: Date: Subject: Cc: To: From: Sender; bh=5+Xq0E9EK519scA6vaX/lUwdzuv3I0cgSK1tWmFZ1y8=; b=IWiUBtUIcLfjFMrnLSVvjd3BqT0qW1VU2HYt9KjmJSPtBUsJmDhfItGqYvZ5FgXIY+Zjv71d 05OZ3oPetbxHnuJm2ZohAn39YX2PiPAbhmjJGxvswF62lQnmeS97+YL6S6t3XAPBlbSh/nLr Dyx8ildQ7dRinhZOhsIRmcW2h4w= X-Mailgun-Sending-Ip: 69.72.43.7 X-Mailgun-Sid: WyIxZTE2YSIsICJsaW51eC11c2JAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n02.prod.us-west-2.postgun.com with SMTP id 5f3cb5f8d96d28d61eeafaf7 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Wed, 19 Aug 2020 05:17:44 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 9706CC433CB; Wed, 19 Aug 2020 05:17:44 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-caf-mail-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=2.0 tests=ALL_TRUSTED,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.0 Received: from wcheng-linux.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: wcheng) by smtp.codeaurora.org (Postfix) with ESMTPSA id 867DAC433CA; Wed, 19 Aug 2020 05:17:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 867DAC433CA Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=none smtp.mailfrom=wcheng@codeaurora.org From: Wesley Cheng To: balbi@kernel.org, gregkh@linuxfoundation.org Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, jackp@codeaurora.org, Wesley Cheng Subject: [PATCH] usb: dwc3: Stop active transfers before halting the controller Date: Tue, 18 Aug 2020 22:17:39 -0700 Message-Id: <20200819051739.22123-1-wcheng@codeaurora.org> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org In the DWC3 databook, for a device initiated disconnect, the driver is required to send dependxfer commands for any pending transfers. In addition, before the controller can move to the halted state, the SW needs to acknowledge any pending events. If the controller is not halted properly, there is a chance the controller will continue accessing stale or freed TRBs and buffers. Signed-off-by: Wesley Cheng --- Verified fix by adding a check for ETIMEDOUT during the run stop call. Shell script writing to the configfs UDC file to trigger disconnect and connect. Batch script to have PC execute data transfers over adb (ie adb push) After a few iterations, we'd run into a scenario where the controller wasn't halted. With the following change, no failed halts after many iterations. --- drivers/usb/dwc3/ep0.c | 2 +- drivers/usb/dwc3/gadget.c | 59 +++++++++++++++++++++++++++++++++++++-- 2 files changed, 57 insertions(+), 4 deletions(-) diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c index 59f2e8c31bd1..456aa87e8778 100644 --- a/drivers/usb/dwc3/ep0.c +++ b/drivers/usb/dwc3/ep0.c @@ -197,7 +197,7 @@ int dwc3_gadget_ep0_queue(struct usb_ep *ep, struct usb_request *request, int ret; spin_lock_irqsave(&dwc->lock, flags); - if (!dep->endpoint.desc) { + if (!dep->endpoint.desc || !dwc->pullups_connected) { dev_err(dwc->dev, "%s: can't queue to disabled endpoint\n", dep->name); ret = -ESHUTDOWN; diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 3ab6f118c508..1f981942d7f9 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -1516,7 +1516,7 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req) { struct dwc3 *dwc = dep->dwc; - if (!dep->endpoint.desc) { + if (!dep->endpoint.desc || !dwc->pullups_connected) { dev_err(dwc->dev, "%s: can't queue to disabled endpoint\n", dep->name); return -ESHUTDOWN; @@ -1926,6 +1926,24 @@ static int dwc3_gadget_set_selfpowered(struct usb_gadget *g, return 0; } +static void dwc3_stop_active_transfers(struct dwc3 *dwc) +{ + u32 epnum; + + for (epnum = 2; epnum < DWC3_ENDPOINTS_NUM; epnum++) { + struct dwc3_ep *dep; + + dep = dwc->eps[epnum]; + if (!dep) + continue; + + if (!(dep->flags & DWC3_EP_ENABLED)) + continue; + + dwc3_remove_requests(dwc, dep); + } +} + static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend) { u32 reg; @@ -1950,16 +1968,37 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend) dwc->pullups_connected = true; } else { + dwc->pullups_connected = false; + + __dwc3_gadget_ep_disable(dwc->eps[0]); + __dwc3_gadget_ep_disable(dwc->eps[1]); + + /* + * The databook explicitly mentions for a device-initiated + * disconnect sequence, the SW needs to ensure that it ends any + * active transfers. + */ + dwc3_stop_active_transfers(dwc); + reg &= ~DWC3_DCTL_RUN_STOP; if (dwc->has_hibernation && !suspend) reg &= ~DWC3_DCTL_KEEP_CONNECT; - - dwc->pullups_connected = false; } dwc3_gadget_dctl_write_safe(dwc, reg); + /* Controller is not halted until pending events are acknowledged */ + if (!is_on) { + reg = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0)); + reg &= DWC3_GEVNTCOUNT_MASK; + if (reg > 0) { + dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), reg); + dwc->ev_buf->lpos = (dwc->ev_buf->lpos + reg) % + dwc->ev_buf->length; + } + } + do { reg = dwc3_readl(dwc->regs, DWC3_DSTS); reg &= DWC3_DSTS_DEVCTRLHLT; @@ -1994,9 +2033,15 @@ static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) } } + /* + * Synchronize and disable any further event handling while controller + * is being enabled/disabled. + */ + disable_irq(dwc->irq_gadget); spin_lock_irqsave(&dwc->lock, flags); ret = dwc3_gadget_run_stop(dwc, is_on, false); spin_unlock_irqrestore(&dwc->lock, flags); + enable_irq(dwc->irq_gadget); return ret; } @@ -3535,6 +3580,14 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt) if (!count) return IRQ_NONE; + /* Controller is halted; ignore new/pending events */ + if (!dwc->pullups_connected) { + dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), count); + dwc->ev_buf->lpos = (dwc->ev_buf->lpos + count) % + dwc->ev_buf->length; + return IRQ_HANDLED; + } + evt->count = count; evt->flags |= DWC3_EVENT_PENDING;