From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bmailout2.hostsharing.net (bmailout2.hostsharing.net [83.223.78.240]) (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 222451649C6 for ; Wed, 1 May 2024 21:50:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.223.78.240 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714600260; cv=none; b=qbbIoXolLtA2JtP/GlpixBa/b2HCrM0ztAiVA/0VNUH7e60L85XE4eL9w7k1J7FmKlfEeP2cineIv9/HiV3Ww1GyVS7wzQt+BJwWeX+d3J+3OZh7RbWH1bBCZrS2RF18u+cDhpGWdOOfuwxzEr5t7oEItP+1NvhOr7eS2oyvYGw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714600260; c=relaxed/simple; bh=XCQWg7aAGZmD+W6VPcRVR/kos4oLwOoeAg3aXIVkUc4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QsUDtMq3qKw7EDMeA8yB4bC+lRlj+Z8PIbEtc8v6V3dqx8821v3ST/SKWA3SxUK1E5Axc1fIrDJkXIgWy/Fp0YcEV+KeWuGEq9Wuo8L1FNVd89W6WNpdsinChz3JPLt7FQ+McEJsBU/a5lo9ZqR84ojEMgohp9ulq2jGB/wvvVg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de; spf=none smtp.mailfrom=h08.hostsharing.net; arc=none smtp.client-ip=83.223.78.240 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=h08.hostsharing.net Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS RSA CA G1" (verified OK)) by bmailout2.hostsharing.net (Postfix) with ESMTPS id 9886228007E3E; Wed, 1 May 2024 23:50:47 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 64BC741166; Wed, 1 May 2024 23:50:47 +0200 (CEST) Date: Wed, 1 May 2024 23:50:47 +0200 From: Lukas Wunner To: Keith Busch Cc: linux-pci@vger.kernel.org, Keith Busch , Suganath Prabu S , Peter Delevoryas Subject: Re: [PATCH] pci: fix broadcom secondary bus reset handling Message-ID: References: <20240501145118.2051595-1-kbusch@meta.com> 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: <20240501145118.2051595-1-kbusch@meta.com> On Wed, May 01, 2024 at 07:51:18AM -0700, Keith Busch wrote: > After a link reset, the Broadcom / LSI PEX890xx PCIe Gen 5 Switch in synth > mode will temporarily insert a fake place-holder device, 1000 02b2, before > the link is actually active for the expected downstream device. Confirm > the device's identifier matches what we expect before moving forward. > Otherwise, the pciehp driver may unmask hotplug notifications before > the link is actually active, which triggers an undesired device removal. This won't work if the device was hot-swapped with a different one and thus correctly returns a different Vendor/Device ID. We'd wait for the device to report the previous device's Vendor/Device ID, which doesn't make sense. It would be possible to raise d3cold_delay in struct pci_dev for children of affected Broadcom switches. Have you considered that as a potential solution? Thanks, Lukas