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 5CDE235959; Wed, 6 Aug 2025 18:15:41 +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=1754504142; cv=none; b=sXfBzcVVab8uaxxdSdNShEpdM2POkm4Xrr38s/kB/PT829sgcdFAVhdvv/lcxH3eHmX8b+G/6g5jvR0Ut2jVbpXvr9FpWYhg3XijANefqdfXJgInCixuT8cm4vtMj7gG39vy2hHF4WWiFy+F5GY4cMgrMV27eWF0+Ivl2wPzwz0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754504142; c=relaxed/simple; bh=YenbEi95ht30tqGvYsUcW/iuqIr6ntv4AaPCVyIWjKk=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=m22iaf9GXh/qCLR8QJ0zPiS3fLL7jl6hKdnl+wMxvWupC2sM6AqosdIIaKugGMQ0ekTXP8EyeX6SS9xxjkktALxm+4zmjXwWMK7s61kIporl69MKdX00tSG3zQBL62L6CN8EgFwmGrwvvzy7nZ/ewzoAzu4Ovl2wbPBQTDPS8W8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Kh1E9NLO; 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="Kh1E9NLO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9517DC4CEE7; Wed, 6 Aug 2025 18:15:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1754504141; bh=YenbEi95ht30tqGvYsUcW/iuqIr6ntv4AaPCVyIWjKk=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=Kh1E9NLODFAYRkV2jJl5UxGQfHDp/VYvJz9snIu0KlC0BLt45MtiIGlWUlg8Qh62u 6v3Ytq11UOaCtwfAYSaWFqGSlrL54FeA8j2dPXj95qsvG72tuD1RdmR6PUI0XPLdcz asbLfqDGi1KMwYVQf4lzcGSH18It7/7cqgn9XFkSwbTMtUXpL7Gt8nxItWVsfE/u7R zI5TskldXNQ02Jlin6O7hiv1H2umRdvwTYjzLTQ9plWAsLTGunj3/ALSlp0XLY1UgR joRyNNz3NntvTIXKqzZevfDiMhwmLD3t1SdydA7AAnU0eZ6fpFpNRD0foYPuLIFn3c Rzf/Upj23IbKw== Date: Wed, 6 Aug 2025 13:15:40 -0500 From: Bjorn Helgaas To: Jim Quinlan Cc: linux-pci@vger.kernel.org, Nicolas Saenz Julienne , Bjorn Helgaas , Lorenzo Pieralisi , Cyril Brulebois , bcm-kernel-feedback-list@broadcom.com, jim2101024@gmail.com, Florian Fainelli , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Manivannan Sadhasivam , Rob Herring , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , open list Subject: Re: [PATCH 2/2] PCI: brcmstb: Add panic/die handler to driver Message-ID: <20250806181540.GA8692@bhelgaas> Precedence: bulk X-Mailing-List: linux-pci@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: <20250613220843.698227-3-james.quinlan@broadcom.com> On Fri, Jun 13, 2025 at 06:08:43PM -0400, Jim Quinlan wrote: > Whereas most PCIe HW returns 0xffffffff on illegal accesses and the like, > by default Broadcom's STB PCIe controller effects an abort. Some SoCs -- > 7216 and its descendants -- have new HW that identifies error details. What's the long term plan for this? This abort is a huge problem that we're seeing across arm64 platforms. Forcing a panic and reboot for every uncorrectable error is pretty hard to deal with. Is there a plan to someday recover from these aborts? Or change the hardware so it can at least be configured to return ~0 data after logging the error in the hardware registers? > This simple handler determines if the PCIe controller was the cause of the > abort and if so, prints out diagnostic info. Unfortunately, an abort still > occurs. > > Care is taken to read the error registers only when the PCIe bridge is > active and the PCIe registers are acceptable. Otherwise, a "die" event > caused by something other than the PCIe could cause an abort if the PCIe > "die" handler tried to access registers when the bridge is off. Checking whether the bridge is active is a "mostly-works" situation since it's always racy. > Example error output: > brcm-pcie 8b20000.pcie: Error: Mem Acc: 32bit, Read, @0x38000000 > brcm-pcie 8b20000.pcie: Type: TO=0 Abt=0 UnspReq=1 AccDsble=0 BadAddr=0