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 87FBAC433FE for ; Mon, 4 Oct 2021 13:15:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6F3DC61A4F for ; Mon, 4 Oct 2021 13:15:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236021AbhJDNRc (ORCPT ); Mon, 4 Oct 2021 09:17:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:55680 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235959AbhJDNP2 (ORCPT ); Mon, 4 Oct 2021 09:15:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C1DBC61B94; Mon, 4 Oct 2021 13:06:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633352774; bh=XErQ9kUZ0Tgqwe22IYQHrapJERMBVej15DCB9EfcK/I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PIYCuVF3WZc7gZcSYG+uSBwNHb258sKsI3gfNAELbqSvd6PNFJ8S1zCii+a28ODd8 ICH+DkAfJEI/jyAjTBZd1AbvF22/8tE6Ve1enWMvc2zI1u+s92EtOyXofuAhKmfbYF JS6w7xame9KHKh1f7Bf6DZaXMD1Azr3YhbXxYCec= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Aswath Govindraju , Pawel Laszczak , Sasha Levin Subject: [PATCH 5.4 04/56] usb: cdns3: fix race condition before setting doorbell Date: Mon, 4 Oct 2021 14:52:24 +0200 Message-Id: <20211004125030.153725747@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211004125030.002116402@linuxfoundation.org> References: <20211004125030.002116402@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 b69ec50b3e55c4b2a85c8bc46763eaf33060584 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_STS_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: # 5.4.x Tested-by: Aswath Govindraju Reviewed-by: Aswath Govindraju Signed-off-by: Pawel Laszczak Signed-off-by: Sasha Levin --- drivers/usb/cdns3/gadget.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/usb/cdns3/gadget.c b/drivers/usb/cdns3/gadget.c index c3bf54cc530f..296f2ee1b680 100644 --- a/drivers/usb/cdns3/gadget.c +++ b/drivers/usb/cdns3/gadget.c @@ -807,6 +807,19 @@ static void cdns3_wa1_tray_restore_cycle_bit(struct cdns3_device *priv_dev, cdns3_wa1_restore_cycle_bit(priv_ep); } +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 @@ -1003,6 +1016,7 @@ int cdns3_ep_run_transfer(struct cdns3_endpoint *priv_ep, /*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)); } -- 2.33.0