From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9492827A476; Thu, 2 Apr 2026 02:23:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775096599; cv=none; b=BNJOMeWlDyGgKD2UPVKjOOxcpIfrkiuRM2hZc0LidCVfsFh0cvfP4F79D8oggaygChE/7Uxsokjc7KG2Px0WRvkaVlHDw5q+gNg0gGg2HPmBEsJ4Td/e4eNzvfEbBSj0WYhBT7/T6BeTs7GLBhGRxQRTIQRkFQmrVf4dwnI5TQE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775096599; c=relaxed/simple; bh=DqjhRKzQGHoJ1MK8NCyZGi/JF0RBID0ZezmBBCyIgi0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=nLTkzECgFbZbHaceNHePq7Cgcg4jFVLxw8dzD7mWTBdHa40uVSMmovUYijhJkpswfl7VTKpmXGYP7TScVvbUmhkNRGl7dU0Q6t/wJz9ySDljiHNHj4bSTdjmz1eB7b/WI3xeMPseZyhApQatCj6KOeB/xTIFvFQuX8S5O9frVG0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fUNVXBvM; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fUNVXBvM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2ED79C4CEF7; Thu, 2 Apr 2026 02:23:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775096599; bh=DqjhRKzQGHoJ1MK8NCyZGi/JF0RBID0ZezmBBCyIgi0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fUNVXBvMitSM1Ek3YerPgTbrzgSqmTdDF4tWOtUgPl4F1KZhADNa4GdPpkESY9F+y 2zLfak1YkQB2L+ficrfQ/SmPgRlVlUHeKBb2D8R8mJlF+bRDuV0iTYLDD8aT1bl8Aq 3C/IsmmnV88MSkNP58ZKgN93p4gqDcp3ZS1yyYCXHuVq+CJnyk2ctwLkkH5qESemWb 7WsZewa/dIvo1b22kQuB+nGNmDTrwDu6zKAB/OsjFVbfHeGxv8K02835W0VRVJV7Gs IOdjJS0l6BLswjMFvpOrdHtl7U/V9+4PEpdh+vIxUaECrrV1lRlNX8MtPRvL51nvfK 51rNTvSeeAdzw== Date: Thu, 2 Apr 2026 10:23:15 +0800 From: "Peter Chen (CIX)" To: Yongchao Wu Cc: pawell@cadence.com, rogerq@kernel.org, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@kernel.org Subject: Re: [PATCH v2] usb: cdns3: gadget: fix state inconsistency on gadget init failure Message-ID: References: <20260401001000.5761-1-yongchao.wu@autochips.com> Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20260401001000.5761-1-yongchao.wu@autochips.com> On 26-04-01 08:10:00, Yongchao Wu wrote: > When cdns3_gadget_start() fails, the DRD hardware is left in gadget mode > while software state remains INACTIVE, creating hardware/software state > inconsistency. > > When switching to host mode via sysfs: > echo host > /sys/class/usb_role/13180000.usb-role-switch/role > > The role state is not set to CDNS_ROLE_STATE_ACTIVE due to the error, > so cdns_role_stop() skips cleanup because state is still INACTIVE. > This violates the DRD controller design specification (Figure22), > which requires returning to idle state before switching roles. > > This leads to a synchronous external abort in xhci_gen_setup() when > setting up the host controller: > > [ 516.440698] configfs-gadget 13180000.usb: failed to start g1: -19 > [ 516.442035] cdns-usb3 13180000.usb: Failed to add gadget > [ 516.443278] cdns-usb3 13180000.usb: set role 2 has failed > ... > [ 1301.375722] xhci-hcd xhci-hcd.1.auto: xHCI Host Controller > [ 1301.377716] Internal error: synchronous external abort: 96000010 [#1] PREEMPT SMP > [ 1301.382485] pc : xhci_gen_setup+0xa4/0x408 > [ 1301.393391] backtrace: > ... > xhci_gen_setup+0xa4/0x408 <-- CRASH > xhci_plat_setup+0x44/0x58 > usb_add_hcd+0x284/0x678 > ... > cdns_role_set+0x9c/0xbc <-- Role switch > > Fix by calling cdns_drd_gadget_off() in the error path to properly > clean up the DRD gadget state. > > Fixes: 7733f6c32e36 ("usb: cdns3: Add Cadence USB3 DRD Driver") > Cc: stable@kernel.org > Signed-off-by: Yongchao Wu Acked-by: Peter Chen Peter > > --- > Changes in v2: > - Update commit title to reflect state inconsistency > - Add more detailed description with error logs > - Add Fixes tag and Cc to stable > --- > drivers/usb/cdns3/cdns3-gadget.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/usb/cdns3/cdns3-gadget.c b/drivers/usb/cdns3/cdns3-gadget.c > index d59a60a16..4cc3f2ffb 100644 > --- a/drivers/usb/cdns3/cdns3-gadget.c > +++ b/drivers/usb/cdns3/cdns3-gadget.c > @@ -3428,6 +3428,7 @@ static int __cdns3_gadget_init(struct cdns *cdns) > ret = cdns3_gadget_start(cdns); > if (ret) { > pm_runtime_put_sync(cdns->dev); > + cdns_drd_gadget_off(cdns); > return ret; > } > > -- > 2.43.0 > > -- Best regards, Peter