From patchwork Thu Sep 3 21:09:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wesley Cheng X-Patchwork-Id: 11755135 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 5E73D618 for ; Thu, 3 Sep 2020 21:10:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 41803206EF for ; Thu, 3 Sep 2020 21:10:48 +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="BO/63UCZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726770AbgICVKr (ORCPT ); Thu, 3 Sep 2020 17:10:47 -0400 Received: from mail29.static.mailgun.info ([104.130.122.29]:41830 "EHLO mail29.static.mailgun.info" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726088AbgICVKq (ORCPT ); Thu, 3 Sep 2020 17:10:46 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1599167444; h=Content-Transfer-Encoding: MIME-Version: Message-Id: Date: Subject: Cc: To: From: Sender; bh=+92L8rCs5Qj2hNgiOrOiCHxci4B2giXkbMRgaJdNbaU=; b=BO/63UCZuxigs9WL3I+0FjC90/LlgvfF4ljgrBfefQ6x2I52ooZqQMvY0KOM3KCUTrvUT0G2 Rg5MZxjeR3Cb2CK1ZKuolau3C3h3mtv9cUxf7TZARdsWlKSj0/sJK5xff/doS9XFr7He/gEK MiOVSP+ndUE58OJ6OaO/e8cIBys= X-Mailgun-Sending-Ip: 104.130.122.29 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-n06.prod.us-west-2.postgun.com with SMTP id 5f515bad25e1ee7586dd7e58 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Thu, 03 Sep 2020 21:10:05 GMT Received: by smtp.codeaurora.org (Postfix, from userid 1001) id D405AC43391; Thu, 3 Sep 2020 21:10:03 +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 87CC8C433C8; Thu, 3 Sep 2020 21:10:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 87CC8C433C8 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, Thinh.Nguyen@synopsys.com Cc: linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, jackp@codeaurora.org, Wesley Cheng Subject: [PATCH v3] usb: dwc3: Stop active transfers before halting the controller Date: Thu, 3 Sep 2020 14:09:54 -0700 Message-Id: <20200903210954.24504-1-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 or bus reset, 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 Reviewed-by: Thinh Nguyen --- Changes in v3: - Removed DWC3_EP_ENABLED check from dwc3_gadget_stop_active_transfers() as dwc3_stop_active_transfer() has a check already in place. - Calling __dwc3_gadget_stop() which ensures that DWC3 interrupt events are cleared, and ep0 eps are cleared for the pullup disabled case. Not required to call __dwc3_gadget_start() on pullup enable, as the composite driver will execute udc_start() before calling pullup(). Changes in v2: - Moved cleanup code to the pullup() API to differentiate between device disconnect and hibernation. - Added cleanup code to the bus reset case as well. - Verified the move to pullup() did not reproduce the problen using the same test sequence. 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 | 49 ++++++++++++++++++++++++++++++++++++++- 2 files changed, 49 insertions(+), 2 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..73bda7eaa773 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 +1926,21 @@ 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; + + dwc3_remove_requests(dwc, dep); + } +} + static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend) { u32 reg; @@ -1971,6 +1986,8 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend) return 0; } +static void __dwc3_gadget_stop(struct dwc3 *dwc); + static int dwc3_gadget_pullup(struct usb_gadget *g, int is_on) { struct dwc3 *dwc = gadget_to_dwc(g); @@ -1994,9 +2011,37 @@ 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); + + /* Controller is not halted until pending events are acknowledged */ + if (!is_on) { + u32 count; + + /* + * 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); + __dwc3_gadget_stop(dwc); + + count = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0)); + count &= DWC3_GEVNTCOUNT_MASK; + if (count > 0) { + dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), count); + dwc->ev_buf->lpos = (dwc->ev_buf->lpos + count) % + dwc->ev_buf->length; + } + } + ret = dwc3_gadget_run_stop(dwc, is_on, false); spin_unlock_irqrestore(&dwc->lock, flags); + enable_irq(dwc->irq_gadget); return ret; } @@ -3100,6 +3145,8 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc) } dwc3_reset_gadget(dwc); + /* Stop any active/pending transfers when receiving bus reset */ + dwc3_stop_active_transfers(dwc); reg = dwc3_readl(dwc->regs, DWC3_DCTL); reg &= ~DWC3_DCTL_TSTCTRL_MASK;