From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7BBD5C61CE8 for ; Thu, 12 Jun 2025 13:20:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:References: List-Owner; bh=TAdRXpfGSSDOCMMR40gtXs0hLQWel8KTicVOiSo+8g8=; b=OTGYYLsQoALqOG daRjS//tKVFdJmFpxyQNYbFVr+NRuqMWPb7VJiQ5HEyiejQLM4/0uL6doUlbSmOZpicow3bp7g6CM 2IK3lBrBCJyZ95ay2pKgDi+tsQWDZzu9pNVenA+yJgW3QY7e0YoKK0omtbEKeD7p2zdh87i/eoqg4 CQ7eYSz/aVb67zBOpQRhfCW72fFSDd5cYoR3HKrTCme4F4yK+OwrsLAe5DpafYobrzQXS9lfPPocP rTAabA8tlo3c7Ctko0LTn31+cJG2s80OUXL5lzBWYriJfaL6MkCPalPWmVg4Ceph55pEtkvJfCReB +MwWlQpMTWrU/K4ZzAqA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uPhrC-0000000DPM3-1ape; Thu, 12 Jun 2025 13:20:38 +0000 Received: from nyc.source.kernel.org ([147.75.193.91]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uPgvg-0000000DElc-2AQn; Thu, 12 Jun 2025 12:21:13 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id D204EA5106A; Thu, 12 Jun 2025 12:21:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D670C4CEEA; Thu, 12 Jun 2025 12:21:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1749730871; bh=D3EDhHkJNow/VmK8m96vIDUE8UN6sG5L/6g1o10X+JI=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=EZYd79dXpn+rewjaoeCT6WVWmMUeWHAfPEgwrs0weSKOwymAkyOOZkP9nObwIVXjf JWsNj3tcCWvNNpHuivmR841FN+4nGpV/sgoMN7nrW/vxH3tlZB11GLISU1A+KU00u+ mIDxMcDikVKp1EGWBNNHFOTGbEHFZghNYR12M+EAM2TGLfIun+FqtKyY/3BiAz/9oX JfABq1y9IiijojH4qHtL5SQuz5OooIvteGg93ijYA9DSL5TmjlUFa1Pq4QiigBKbrW pJb8h79uxLdzoH1QTJJrzedSJo8zZfaSoHUz4q0cjmJCjeR9KYP385fOpLAvOtRJG7 eT35UGvi6pQVg== Date: Thu, 12 Jun 2025 07:21:08 -0500 From: Bjorn Helgaas To: Niklas Cassel Cc: Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Manivannan Sadhasivam , Rob Herring , Bjorn Helgaas , Heiko Stuebner , Wilfred Mallawa , Damien Le Moal , Laszlo Fiat , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org Subject: Re: [PATCH 1/4] PCI: dw-rockchip: Do not enumerate bus before endpoint devices are ready Message-ID: <20250612122108.GA901642@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250612_052112_619695_DA505D7C X-CRM114-Status: GOOD ( 23.66 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Jun 12, 2025 at 01:40:23PM +0200, Niklas Cassel wrote: > On Thu, Jun 12, 2025 at 06:38:27AM -0500, Bjorn Helgaas wrote: > > On Thu, Jun 12, 2025 at 01:19:45PM +0200, Niklas Cassel wrote: > > > On Wed, Jun 11, 2025 at 04:14:56PM -0500, Bjorn Helgaas wrote: > > > > On Wed, Jun 11, 2025 at 12:51:42PM +0200, Niklas Cassel wrote: > > > > > Commit ec9fd499b9c6 ("PCI: dw-rockchip: Don't wait for link since we can > > > > > detect Link Up") changed so that we no longer call dw_pcie_wait_for_link(), > > > > > and instead enumerate the bus directly after receiving the Link Up IRQ. > > > > > > > > > > This means that there is no longer any delay between link up and the bus > > > > > getting enumerated. > > > > > > I think the comment at the PCIE_T_RRS_READY_MS definition should be > > > > enough (although it might need to be updated to mention link-up). > > > > This delay is going to be a standard piece of every driver, so it > > > > won't require special notice. > > > > > > Looking at pci.h, we already have a comment mentioning exactly this > > > (link-up): > > > https://github.com/torvalds/linux/blob/v6.16-rc1/drivers/pci/pci.h#L51-L63 > > > > > > I will change the patches to use PCIE_RESET_CONFIG_DEVICE_WAIT_MS instead. > > > > I'll more closely later, but I think PCIE_T_RRS_READY_MS and > > PCIE_RESET_CONFIG_DEVICE_WAIT_MS are duplicates and only one should > > exist. It looks like they got merged at about the same time by > > different people, so we didn't notice. > > I came to the same conclusion, I will send a patch to remove > PCIE_T_RRS_READY_MS and convert the only existing user to use > PCIE_RESET_CONFIG_DEVICE_WAIT_MS. I think PCIE_T_RRS_READY_MS expresses the purpose of the wait more specifically. It's not that the device is completely ready after 100ms; just that it should be able to respond with RRS if it needs more time.