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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CB84DC43334 for ; Tue, 19 Jul 2022 12:02:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237970AbiGSMCh (ORCPT ); Tue, 19 Jul 2022 08:02:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237853AbiGSMB6 (ORCPT ); Tue, 19 Jul 2022 08:01:58 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DB6854AD71; Tue, 19 Jul 2022 04:58:52 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 89BCDB81A2E; Tue, 19 Jul 2022 11:58:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDA26C341C6; Tue, 19 Jul 2022 11:58:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1658231930; bh=AuBuzGhApDy8fArqUJwljo8Tnm+BNRAQ/o6uRm5qtt0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SDJgLnniGSz/Tcmv9j0rhpQsHFcTl+4Jz4R71zqg9OxG0pIFLCDoR9kw5+vDiPwi6 2ZC9cnxvCsWqa2f8JQ8w/zh6yvdVCp8BWMhPcpg4sXQxbk8dbfASkR5M8rWu0IVx/e th4Ha5AQm/u1i5oCffmmqDrvbSPWzBQlc7WYNucA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thinh Nguyen Subject: [PATCH 4.14 39/43] usb: dwc3: gadget: Fix event pending check Date: Tue, 19 Jul 2022 13:54:10 +0200 Message-Id: <20220719114525.278681956@linuxfoundation.org> X-Mailer: git-send-email 2.37.1 In-Reply-To: <20220719114521.868169025@linuxfoundation.org> References: <20220719114521.868169025@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thinh Nguyen commit 7441b273388b9a59d8387a03ffbbca9d5af6348c upstream. The DWC3_EVENT_PENDING flag is used to protect against invalid call to top-half interrupt handler, which can occur when there's a delay in software detection of the interrupt line deassertion. However, the clearing of this flag was done prior to unmasking the interrupt line, creating opportunity where the top-half handler can come. This breaks the serialization and creates a race between the top-half and bottom-half handler, resulting in losing synchronization between the controller and the driver when processing events. To fix this, make sure the clearing of the DWC3_EVENT_PENDING is done at the end of the bottom-half handler. Fixes: d325a1de49d6 ("usb: dwc3: gadget: Prevent losing events in event cache") Cc: stable@vger.kernel.org Signed-off-by: Thinh Nguyen Link: https://lore.kernel.org/r/8670aaf1cf52e7d1e6df2a827af2d77263b93b75.1656380429.git.Thinh.Nguyen@synopsys.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/dwc3/gadget.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -3130,7 +3130,6 @@ static irqreturn_t dwc3_process_event_bu } evt->count = 0; - evt->flags &= ~DWC3_EVENT_PENDING; ret = IRQ_HANDLED; /* Unmask interrupt */ @@ -3143,6 +3142,9 @@ static irqreturn_t dwc3_process_event_bu dwc3_writel(dwc->regs, DWC3_DEV_IMOD(0), dwc->imod_interval); } + /* Keep the clearing of DWC3_EVENT_PENDING at the end */ + evt->flags &= ~DWC3_EVENT_PENDING; + return ret; }