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 01E5F4086A; Wed, 28 Jan 2026 08:56:21 +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=1769590582; cv=none; b=iH6TrDzRH5q7vJgq2XS2JtK1/iGKeHy7CdAqPxNpOGEx8Je8T/Wtgf2dz2KzLz4fBf1O89tRgnKmsLXUvDs5+24rX8SNYy8psNNnVOFkC0mP9s8z40fXdS037/HCbhMNoIcSGfBisdRO+raCXb8qBvmTgk6G2boTsHkB8k8Amk4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769590582; c=relaxed/simple; bh=GWyCmUt+R4JArRQYceZDS1fFYiZJd/juPN0plXPMWVg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=aSbdvPRWlCLNmV3/eQPgcXbFQ2np+TRbIpHSw0Yob4vYPQsHwGn+rNY/zufFXPy9XQovDysKmLiZJfvWexeB4v0Ml2MZrRHHmlHVwekZ6Zym/0Ccm7JJSzXGQoE/RwchhuHkGMMMv+ioaZvmm0PCAPArEinn9r3NX7+4XPK9ci0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=oEJne041; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="oEJne041" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23688C4CEF1; Wed, 28 Jan 2026 08:56:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1769590581; bh=GWyCmUt+R4JArRQYceZDS1fFYiZJd/juPN0plXPMWVg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=oEJne041LsinxJzPKLsKl1BgaQQeZgHE/zjdWoMeGnYFBw8ZGtbdPRld8CwH268lO wl9Fek2nkEUWnNegG7UO255oXGM8+ekiYb4hRu+ofK4BjlkkRs9+XR/JkXxPp7ns+N OtSt+8bLkqH/iFOv53p5VxueRdh0ABq2tJ32T4oY= Date: Wed, 28 Jan 2026 09:56:18 +0100 From: Greg Kroah-Hartman To: Dayu Jiang Cc: Mathias Nyman , Longfang Liu , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, yudongbin , guhuinan , chenyu45 , mahongwei3 Subject: Re: [PATCH] usb: xhci: add xhci_halt() for HCE Handling Message-ID: <2026012857-deprive-putdown-0ee8@gregkh> References: <20260127110422.306711-1-jiangdayu@xiaomi.com> <2026012708-liability-sincere-5ed4@gregkh> 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=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jan 28, 2026 at 04:48:49PM +0800, Dayu Jiang wrote: > On Tue, Jan 27, 2026 at 12:22:40PM +0100, Greg Kroah-Hartman wrote: > > > if (status & STS_HCE) { > > > xhci_warn(xhci, "WARNING: Host Controller Error\n"); > > > + xhci_halt(xhci); > > > > What is going to start things back up again? And as you are calling > > this function, why is the warning message needed anymore? The > > tracepoint information will give you that message now, right? > When HCE is triggered, it indicates a critical hardware failure. > Aligning with the handling of HSE (STS_FATAL) by adding > xhci_halt() here is more reasonable: without xhci_halt(), the > USB controller may fall into an unpredictable and unstable state, > which could exacerbate system issues. > > Retaining the warning message is necessary because it is directly > visible in dmesg, whereas tracepoint information requires explicitly > enabling xHCI tracepoints. Additionally, if xhci_halt() is called in > xhci_irq() without the warning log, it would be impossible to > distinguish whether the halt was triggered by HCE or HSE. > > > > And is this just papering over a hardware bug? Should this really be > > happening for any normal system? > Yes, this issue has been reproducible on real-world hardware: HCE is > triggered in UAS Storage Device plug/unplug scenarios on Android > devices, which enters this error branch and causes an interrupt storm, > leading to severe system-level faults. Great, please provide this information in the changelog text when you resubmit this, thanks! greg k-h