From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793964969; b=SiYJ+rH/fJypMDjg7Sx+YHL0fiOqwUVOWyQ8E5oB7rHOnr/nAaHdag6nUC5+o7bPf4gh FaelWjYsjqX6wnnR3rWCJAQGDpXdsE8Ks6VOaHVmF3ca9USWKJLADBsknSH7Dw53CdhWY TQBsDS+N2H4vUx9TZ/Gq3IeMmO1JS0QCZXIb9W4RZgo2fOjHSy7GmuEf+xXjjUXkTBZBs SzJ4NKlENXhaNYjEa3IZ4OfKRNL7nnJDq53+PspDtoy8Ah68edE1DJDJqtzDpkZDwtCao 2Qwt6DaUhbypuNeLcQN8gEC4WWQrDSM3NqfXkPCB+0/XE/KVXpcJRg+nCzZfbiFctkQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793964969; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=MxrX/3YFwvUn5AWi3UIy5vUn8XO00+EiZlHIlqf6qwE=; b=KhhsoAFEM07l2QxvKsbM5zJwLOAZ/672npnsF8U+6QQ+uogSTRFts+QBwDWRey68urov D3dijYs54QS8VgUrCfXe6uitCCvDiXX9i/IpLtblp1oZPyMxxiPNWJPVlfqrrPssaT6Ul 8iHPsSaXUiltOPKKbvOIvBGL0uqjDrGWj3fJspaMPwuB4RS3z2YBOQaxtEdqh450S2ZrO gP8y1rjzqJDY/GJax96DXuCqWW5bpkpd01UC1Kzo2OSWDSI+gTJveoGsTMbXpwbGC5tjO S+KSC/jehVtTlQ5lrY5cNzSX2J0d4AqvGLZWsScVWKxp5ZHiB/lDidTHcAHbJ6/B8Og== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lRHVVQ7I; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C2084606BD4C for ; Fri, 6 Nov 2026 11:36:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=lRHVVQ7I Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3602C1F008A1; Fri, 6 Nov 2026 11:36:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793964968; bh=MxrX/3YFwvUn5AWi3UIy5vUn8XO00+EiZlHIlqf6qwE=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=lRHVVQ7IDTx3LFFiXi+r7jkZfuykXihwLnQQxZs7V18HqURAsS/oSQe7EoMMI04yh NTwgYK/F/nzstlxz6LqSc+Rnz7alY2TUWFkRsEnU5V54aBasCUg1i9a9CppCh1qwPL BIi1ekHrZqqFAGwwzP/iopYrTTZGx6AwBEp9VkH6L+6N+fhqpx2eZyuxwKk6vZn3XC 9xcWPxGWnOGC82WN6qe+X9cv/7FO1JIeSAxAmiIm2PJ6241XE3lp2zvBBi+DQRUsPH gi4Eq8EduKvDIDx/nXBXiQU1ejqYPTi34MoU4pOjoAdck+Bvy/lud0dG1E4SmNwEfg QN/V9VxX6FcgQ== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH 1/2] usb: dwc3: wait for the port to leave RxDetect before xHCI reset Reply-To: sashiko-reviews@lists.linux.dev To: "Xu Yang" Cc: linux-usb@vger.kernel.org In-Reply-To: <20261106111943.2868733-2-xu.yang_2@oss.nxp.com> References: <20261106111943.2868733-1-xu.yang_2@oss.nxp.com> <20261106111943.2868733-2-xu.yang_2@oss.nxp.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 06 Nov 2026 11:36:07 +0000 X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Xu Yang >=20 > When the host controller loses power during system suspend, the port > state is not retained. After power is restored, the port starts in the > Disconnected (RxDetect) state instead of its previous Enabled (U3) > state. >=20 > After the controller is switched back to host mode, testing on an i.MX8/9 > SoC shows that it takes about 2 ms for the port to leave RxDetect and > enter Polling. If xHCI is reset while the port is still in RxDetect, the > port does not issue a Warm Reset. >=20 > This prevents the link from recovering because the USB3 device may > still be in U3. Once the port enters Polling, it sends LFPS.Polling, but > the device does not respond as expected. After three Polling attempts, > each taking about 360 ms (tPollingLFPSTimeout), the controller reports > the device as disconnected. >=20 > If xHCI is reset after the port has entered Polling, the port issues a > Warm Reset and the link recovers quickly after the device responds. >=20 > Add a 2 ms delay through the xHCI resume quirk before resetting xHCI. > This allows the port to leave RxDetect so that a Warm Reset can be > issued, avoiding an unnecessary device disconnect during system > resume. >=20 > Signed-off-by: Xu Yang Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261106111943.2868= 733-1-xu.yang_2@oss.nxp.com?part=3D1