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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0485DC4167B for ; Mon, 27 Sep 2021 17:22:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E9C986128A for ; Mon, 27 Sep 2021 17:22:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237633AbhI0RXY (ORCPT ); Mon, 27 Sep 2021 13:23:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:35430 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237081AbhI0RUb (ORCPT ); Mon, 27 Sep 2021 13:20:31 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 58701611F0; Mon, 27 Sep 2021 17:13:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1632762803; bh=69Uxtxgyff81kJqEEoa933+6XTWO0/G3EDLXaWooPU0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1lJoiimZn/l/ILQOBm8NREmOVTitjWEUlximdDrHC4rzzZ6GAe0bh4hmP3BI70z/9 5XGfMXkPVBrtFNkGUUchhzdDR4Brdn/UwO5m1JSxGdKAsGNu4wIK9KNUefIwxeuTxw eH07eTOT5BUBiZz8QOzIigJmzfbo11ozfIMHqcgk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Aswath Govindraju , Pawel Laszczak Subject: [PATCH 5.14 024/162] usb: cdns3: fix race condition before setting doorbell Date: Mon, 27 Sep 2021 19:01:10 +0200 Message-Id: <20210927170234.300838423@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210927170233.453060397@linuxfoundation.org> References: <20210927170233.453060397@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: Pawel Laszczak commit b69ec50b3e55c4b2a85c8bc46763eaf330605847 upstream. For DEV_VER_V3 version there exist race condition between clearing ep_sts.EP_STS_TRBERR and setting ep_cmd.EP_CMD_DRDY bit. Setting EP_CMD_DRDY will be ignored by controller when EP_STS_TRBERR is set. So, between these two instructions we have a small time gap in which the EP_STSS_TRBERR can be set. In such case the transfer will not start after setting doorbell. Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver") cc: # 5.12.x Tested-by: Aswath Govindraju Reviewed-by: Aswath Govindraju Signed-off-by: Pawel Laszczak Link: https://lore.kernel.org/r/20210907062619.34622-1-pawell@gli-login.cadence.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/cdns3/cdns3-gadget.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/drivers/usb/cdns3/cdns3-gadget.c +++ b/drivers/usb/cdns3/cdns3-gadget.c @@ -1100,6 +1100,19 @@ static int cdns3_ep_run_stream_transfer( return 0; } +static void cdns3_rearm_drdy_if_needed(struct cdns3_endpoint *priv_ep) +{ + struct cdns3_device *priv_dev = priv_ep->cdns3_dev; + + if (priv_dev->dev_ver < DEV_VER_V3) + return; + + if (readl(&priv_dev->regs->ep_sts) & EP_STS_TRBERR) { + writel(EP_STS_TRBERR, &priv_dev->regs->ep_sts); + writel(EP_CMD_DRDY, &priv_dev->regs->ep_cmd); + } +} + /** * cdns3_ep_run_transfer - start transfer on no-default endpoint hardware * @priv_ep: endpoint object @@ -1351,6 +1364,7 @@ static int cdns3_ep_run_transfer(struct /*clearing TRBERR and EP_STS_DESCMIS before seting DRDY*/ writel(EP_STS_TRBERR | EP_STS_DESCMIS, &priv_dev->regs->ep_sts); writel(EP_CMD_DRDY, &priv_dev->regs->ep_cmd); + cdns3_rearm_drdy_if_needed(priv_ep); trace_cdns3_doorbell_epx(priv_ep->name, readl(&priv_dev->regs->ep_traddr)); }