From patchwork Thu May 20 20:22:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alan Stern X-Patchwork-Id: 12271353 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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 1A0B3C433ED for ; Thu, 20 May 2021 20:22:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1C366135C for ; Thu, 20 May 2021 20:22:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236192AbhETUXY (ORCPT ); Thu, 20 May 2021 16:23:24 -0400 Received: from netrider.rowland.org ([192.131.102.5]:41495 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S236062AbhETUXW (ORCPT ); Thu, 20 May 2021 16:23:22 -0400 Received: (qmail 1217378 invoked by uid 1000); 20 May 2021 16:22:00 -0400 Date: Thu, 20 May 2021 16:22:00 -0400 From: Alan Stern To: Felipe Balbi Cc: USB mailing list Subject: [PATCH 3/4] USB: UDC: Implement udc_async_callbacks in net2280 Message-ID: <20210520202200.GE1216852@rowland.harvard.edu> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org This patch adds a udc_async_callbacks handler to the net2280 UDC driver, which will prevent a theoretical race during gadget unbinding. The net2280 driver is sufficiently complicated that I didn't want to mess around with IRQ settings. Instead, the patch simply adds a new flag to control async callbacks, and checks the flag before issuing any of them. Signed-off-by: Alan Stern Acked-by: Felipe Balbi --- [as1958] drivers/usb/gadget/udc/net2280.c | 49 +++++++++++++++++++++++++-------------- drivers/usb/gadget/udc/net2280.h | 1 2 files changed, 33 insertions(+), 17 deletions(-) Index: usb-devel/drivers/usb/gadget/udc/net2280.c =================================================================== --- usb-devel.orig/drivers/usb/gadget/udc/net2280.c +++ usb-devel/drivers/usb/gadget/udc/net2280.c @@ -1617,6 +1617,7 @@ static struct usb_ep *net2280_match_ep(s static int net2280_start(struct usb_gadget *_gadget, struct usb_gadget_driver *driver); static int net2280_stop(struct usb_gadget *_gadget); +static void net2280_async_callbacks(struct usb_gadget *_gadget, bool enable); static const struct usb_gadget_ops net2280_ops = { .get_frame = net2280_get_frame, @@ -1625,6 +1626,7 @@ static const struct usb_gadget_ops net22 .pullup = net2280_pullup, .udc_start = net2280_start, .udc_stop = net2280_stop, + .udc_async_callbacks = net2280_async_callbacks, .match_ep = net2280_match_ep, }; @@ -2472,7 +2474,7 @@ static void stop_activity(struct net2280 nuke(&dev->ep[i]); /* report disconnect; the driver is already quiesced */ - if (driver) { + if (dev->async_callbacks && driver) { spin_unlock(&dev->lock); driver->disconnect(&dev->gadget); spin_lock(&dev->lock); @@ -2502,6 +2504,15 @@ static int net2280_stop(struct usb_gadge return 0; } +static void net2280_async_callbacks(struct usb_gadget *_gadget, bool enable) +{ + struct net2280 *dev = container_of(_gadget, struct net2280, gadget); + + spin_lock_irq(&dev->lock); + dev->async_callbacks = enable; + spin_unlock_irq(&dev->lock); +} + /*-------------------------------------------------------------------------*/ /* handle ep0, ep-e, ep-f with 64 byte packets: packet per irq. @@ -3042,9 +3053,11 @@ usb3_delegate: readl(&ep->cfg->ep_cfg)); ep->responded = 0; - spin_unlock(&dev->lock); - tmp = dev->driver->setup(&dev->gadget, &r); - spin_lock(&dev->lock); + if (dev->async_callbacks) { + spin_unlock(&dev->lock); + tmp = dev->driver->setup(&dev->gadget, &r); + spin_lock(&dev->lock); + } } do_stall3: if (tmp < 0) { @@ -3284,9 +3297,11 @@ delegate: w_value, w_index, w_length, readl(&ep->cfg->ep_cfg)); ep->responded = 0; - spin_unlock(&dev->lock); - tmp = dev->driver->setup(&dev->gadget, &u.r); - spin_lock(&dev->lock); + if (dev->async_callbacks) { + spin_unlock(&dev->lock); + tmp = dev->driver->setup(&dev->gadget, &u.r); + spin_lock(&dev->lock); + } } /* stall ep0 on error */ @@ -3391,14 +3406,14 @@ __acquires(dev->lock) if (disconnect || reset) { stop_activity(dev, dev->driver); ep0_start(dev); - spin_unlock(&dev->lock); - if (reset) - usb_gadget_udc_reset - (&dev->gadget, dev->driver); - else - (dev->driver->disconnect) - (&dev->gadget); - spin_lock(&dev->lock); + if (dev->async_callbacks) { + spin_unlock(&dev->lock); + if (reset) + usb_gadget_udc_reset(&dev->gadget, dev->driver); + else + (dev->driver->disconnect)(&dev->gadget); + spin_lock(&dev->lock); + } return; } } @@ -3419,12 +3434,12 @@ __acquires(dev->lock) writel(tmp, &dev->regs->irqstat1); spin_unlock(&dev->lock); if (stat & BIT(SUSPEND_REQUEST_INTERRUPT)) { - if (dev->driver->suspend) + if (dev->async_callbacks && dev->driver->suspend) dev->driver->suspend(&dev->gadget); if (!enable_suspend) stat &= ~BIT(SUSPEND_REQUEST_INTERRUPT); } else { - if (dev->driver->resume) + if (dev->async_callbacks && dev->driver->resume) dev->driver->resume(&dev->gadget); /* at high speed, note erratum 0133 */ } Index: usb-devel/drivers/usb/gadget/udc/net2280.h =================================================================== --- usb-devel.orig/drivers/usb/gadget/udc/net2280.h +++ usb-devel/drivers/usb/gadget/udc/net2280.h @@ -162,6 +162,7 @@ struct net2280 { ltm_enable:1, wakeup_enable:1, addressed_state:1, + async_callbacks:1, bug7734_patched:1; u16 chiprev; int enhanced_mode;