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 97A10CEE343 for ; Tue, 18 Nov 2025 18:59:28 +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=l5bV2Z4OjyhUjLyzKUG06uKyhqe2xLFxXRvaaVkwXWk=; b=uS1Ijp489C9GB0 /kQtnuRQXEqfP+Bt2bLapf4b2Zlrf4WItZWokwy55ZN51jDpnceiqu9GiONsxk0EgvBYxwv3CRDJh tYhp9o3hBJLKh7yg5hwL0opgvHtUaXsvfdfjzAVSirce+RZH5s4WbhvA4a9L+TcCtctywiWt4XN1b JQjOy7/Ymmba8mvGUhbvZEpJTx/Nrfo9tBcxb5S/3+c9brYOBkUGQPXRKwDPVuNAhfY2GikHHftWZ M1RYqCQKAe4MWVKjO0BzmaKEyeE/EH/2NJSl/NATgQVyG2VKOw+Cmy6TXhQN27AZotiFyKJ7GrxX4 f7qN5TZ3HF2bu/783xxA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vLQvC-00000000zaU-1uvv; Tue, 18 Nov 2025 18:59:22 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vLQvB-00000000zZq-0BAa; Tue, 18 Nov 2025 18:59:21 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 264EF60129; Tue, 18 Nov 2025 18:59:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3DFA5C116B1; Tue, 18 Nov 2025 18:59:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763492359; bh=NbYnGS0Gvtjj0O/ATTHE0hLak4XPDCCvFVuevEBXAKo=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=gRLVw75DZQRIC199NZP0+fLbXt5NziqDfA46T2DPhbBdDCtPYCBZfyyWW7UyRsEPw GVhheTS/RHFWMtANriPle8VTPUpebveAg/3fb4u/2eR7YIwxG0U6BENqJKIkLqshnI dmwF4WRPdFYFg7+thS2DyveG++gO2YeKAqNLmknGP/GdluG6MgbL7QMpK7s6eSXXys uoIUgoUiOpcFIOAGpfEWAeed4vMD1w+KY64OBxXUMmhj8wVcIuJhrVz7SqwJ+64A/z IvTrkxaPYm6ZcvxJMyP+tmwp2NOWXkblLJ2u0AzGcqDPslPXW7NukPPm1uFlTmPpR3 9XKOpyQpf81Xw== Date: Tue, 18 Nov 2025 12:59:17 -0600 From: Bjorn Helgaas To: Niklas Cassel Cc: Shawn Lin , Manivannan Sadhasivam , Lorenzo Pieralisi , Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= , Rob Herring , Heiko Stuebner , Kever Yang , Simon Xue , Damien Le Moal , Dragan Simic , FUKAUMI Naoki , Diederik de Haas , Richard Zhu , Frank Li , Lucas Stach , Shawn Guo , Sascha Hauer , Fabio Estevam , Conor Dooley , Krzysztof Kozlowski , Thierry Reding , Jonathan Hunter , Hans Zhang , linux-tegra@vger.kernel.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, kernel@pengutronix.de, Bjorn Helgaas Subject: Re: [PATCH 2/4] PCI: tegra194: Remove unnecessary L1SS disable code Message-ID: <20251118185917.GA2583698@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Wed, Nov 12, 2025 at 09:29:20AM +0100, Niklas Cassel wrote: > On Tue, Nov 11, 2025 at 04:16:09PM -0600, Bjorn Helgaas wrote: > > From: Bjorn Helgaas > > > > The DWC core clears the L1 Substates Supported bits unless the driver sets > > the "dw_pcie.l1ss_support" flag. > > > > The tegra194 init_host_aspm() sets "dw_pcie.l1ss_support" if the platform > > has the "supports-clkreq" DT property. If "supports-clkreq" is absent, > > "dw_pcie.l1ss_support" is not set, and the DWC core will clear the L1 > > Substates Supported bits. > > > > The tegra194 code to clear the L1 Substates Supported bits is unnecessary, > > so remove it. > > > > Signed-off-by: Bjorn Helgaas > > --- > > Since init_host_aspm() is now the only place using struct tegra_pcie_dw > struct member cfg_link_cap_l1sub, I think that you can remove this struct > member, and instead make this a local variable in init_host_aspm(). It looks like tegra_pcie_ep_irq_thread() also uses it, although I'm dubious about that. It's odd that software would be responsible for sending LTR messages, but I guess this only happens for tegra194_pcie_dw_ep_of_data, and apparently it's fixed (".has_ltr_req_fix" for tegra234. And odd that we would read the capability register on every interrupt even though this driver is the only thing that can change it, so we should be able to cache the value in init_host_aspm().