From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 77D9437F339 for ; Sat, 3 Oct 2026 01:33:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790991233; cv=none; b=oqbHMwbRF8IG1dFVBYKHqbJbhrgPNH4K/LvRf/xf2143OdPvrzGIefNVuMHrAcDmm3K4nBRYzJiBlfJwzAp9ux87fhEQAjfYDJ8VfHiqBmPQt+7zPrbGI80NB9gtSriElQPPw6Y/zWvaSMQ78/c9lgmw2SNLUjRiYH30rJmAKh0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790991233; c=relaxed/simple; bh=wXnKL+UDwnJRbnC7leHSOKKN3Zt2B2ofzp+E0UyxRF8=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=N+ElwAsIM3YhyAS4U6evD7BMVV6I0lvvFmyQlIvoBeiermZNgSc0cz3s6zyayBA4IXSocMcqdxFhr7BN4VuuI8B/jawsXYcdJErFJp4jbXVzJ7L2SZuV+H08wRRJ+3KKTYsXwSGVwN05JblSl5RRJ6RfFW0VrezJ6PFVn+BN4uc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=MV0YB934; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="MV0YB934" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 076F01F00899; Sat, 3 Oct 2026 01:33:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790991232; bh=Da3BEO9KsLueBBN2DERziDzqaJN0hVnaQ1xo5nUnQig=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=MV0YB934SKLxEodjutXJXQkniZE1wEHeRBhPWI7Cs+bWsdwzv3lFzk5tHj3WFXNI1 9U3GVGKYoFMVya4ycUHg37MTjZFYBo4FwM0KiOe5EP8dGYScTeo7eqgvhkjKAvbCLf qMcjHw1kfePsfGVhJnX0jnmSt1T1jj0opagzB6IInEKKR51rSR90prqVMT+T8KKskc h+o3wPlV/kY12jCOA6dGn5vyFx5XWKZpmL5Zzkm0kMNS+87tG99dK3S7weNLcTXWjs e2Dqocwrw/8pO3v2JYvYFYvS3wqQ6+fW0LN7NyzScl0QrYnVDK64Ll/AHmCLLAsVL6 sSRjrA6KWabEA== From: sashiko-bot@kernel.org Subject: Re: [RFC PATCH 1/2] PCI: Add pci=hpreserve= to reserve memory windows for a hotplug bridge Reply-To: sashiko-reviews@lists.linux.dev To: "Maciej Grochowski" Cc: linux-pci@vger.kernel.org In-Reply-To: <20261002193111.51637-2-maciej.grochowski@sony.com> References: <20261002193111.51637-1-maciej.grochowski@sony.com> <20261002193111.51637-2-maciej.grochowski@sony.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sat, 03 Oct 2026 01:33:51 +0000 Message-Id: <20261003013352.076F01F00899@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > A hotplug bridge is sized for the devices that are present when its > windows are sized, plus the optional hpmmiosize/hpmmioprefsize space. > Some topologies have devices that are known to appear later. After a > reset of a two-level PCIe switch hierarchy, for example, pciehp > re-enumerates the upstream switch before the link to the nested switch > is back up, so the downstream port leading to the nested switch is > sized with nothing below it. When the nested switch appears, its BARs > do not fit. >=20 > On a two-level Microchip PM50052 (Switchtec PFX) hierarchy whose nested > switch has an NTB function with a 1 GiB prefetchable BAR, a hard reset > of the top-level switch on v7.3-rc2 leaves downstream port 82:03.0 > with a 206 MiB prefetchable window, an equal share of its > parent's window. The nested switch returns about 0.6 s later and > fails: > [ ... ] >=20 > Without the parameter nothing changes. >=20 > Tested-by: Maciej Grochowski > Signed-off-by: Maciej Grochowski Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261002193111.5163= 7-1-maciej.grochowski@sony.com?part=3D1