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 96071390999; Mon, 2 Mar 2026 23:34:03 +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=1772494443; cv=none; b=nc3ih00v7n2mjlk877ZV55NAICDgMxKvTVf1OSkxUwwl1uPQSA4HoQyghOFyJ4Qv+HFfwC67scoSWB/QrvHJNBUpTTfNrSEjvbWT04Cv+y1R486sjG3ipKKNvx06FMti/1TeDJ1pPSjs4OY8YHg2UD5iwD1gUCM4sXmaCd+V+zg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772494443; c=relaxed/simple; bh=mL6f56HgyQO2Y7b3yScPWfCJ2EH+1ll0FYkWzkDjtPA=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=c03tLBVQqLknP8C+kdGfQPu9OxUygamflp8zGBxbbJrqxBqs5U/L7Abiv9bVkqr8DY8mUmyQB2MjLFXdCBGeephFzhOzWhvpAvwe5llavzu8oiNZxJG6WTJfzeYPJB+T1CIX/3Ulb7f+UjmaNNrycIx5GyKyR1PO2lb7Pgo9BMY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hgwRz9mo; 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="hgwRz9mo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E26C9C19423; Mon, 2 Mar 2026 23:34:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772494443; bh=mL6f56HgyQO2Y7b3yScPWfCJ2EH+1ll0FYkWzkDjtPA=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=hgwRz9mo1f6P8lEaYvZLYQSexkcYULCY412yJXRHh8WsDcaGflxIaqXD0rytVzK8U kLKPoOZ3GddfXKEdvKKlTvkVEM8j9pOoHByDdtwVpCSS1W98FfjtLG1xKXbHTOCRxL WealVtc3Z64TH/4TIfMdymDmXy5x+GxgLK8JvO8n6TP5bA3y91wNFOH+RGlliY5JPL jbwxLv+ShytokK7eZASQT+naboVkF/HXkSY9Oydaz05uMydcoG1f5FBOTWpJvI2k24 Et35Y6XrUk+vK/GcChk3aRI832rESHc7C5ZTmnulO8I3UGiRmFv+65RDOPpJdrr1lw wu8vURfkKyLUw== Date: Mon, 2 Mar 2026 17:34:01 -0600 From: Bjorn Helgaas To: Vidya Sagar Cc: Manikanta Maddireddy , "bhelgaas@google.com" , "lpieralisi@kernel.org" , "kwilczynski@kernel.org" , "mani@kernel.org" , "robh@kernel.org" , "krzk+dt@kernel.org" , "conor+dt@kernel.org" , "thierry.reding@gmail.com" , Jon Hunter , "kishon@kernel.org" , "arnd@arndb.de" , "gregkh@linuxfoundation.org" , "Frank.Li@nxp.com" , "den@valinux.co.jp" , "hongxing.zhu@nxp.com" , "jingoohan1@gmail.com" , "cassel@kernel.org" , "18255117159@163.com" <18255117159@163.com>, "linux-pci@vger.kernel.org" , "linux-tegra@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v6 1/9] PCI: tegra194: Drive CLKREQ signal low explicitly Message-ID: <20260302233401.GA4036986@bhelgaas> Precedence: bulk X-Mailing-List: linux-tegra@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: <2b1f2d0f-b07d-4b14-ac19-78112ca84f05@nvidia.com> On Fri, Feb 27, 2026 at 12:35:31PM +0000, Vidya Sagar wrote: > On 24/02/26 00:15, Manikanta Maddireddy wrote: > > From: Vidya Sagar > > > > Currently, the default setting is that CLKREQ signal of a Root Port > > is internally overridden to '0' to enable REFCLK to flow out to the slot. > > It is observed that one of the PCIe switches (case in point Broadcom PCIe > > Gen4 switch) is propagating the CLKREQ signal of the root port to the > > downstream side of the switch and expecting the endpoints to pull it low > > so that it (PCIe switch) can give out the REFCLK although the Switch as > > such doesn't support CLK-PM or ASPM-L1SS. So, as a workaround, this patch > > drives the CLKREQ of the Root Port itself low to avoid link up issues > > between PCIe switch downstream port and endpoints. This is not a wrong > > thing to do after all the CLKREQ is anyway being overridden to '0' > > internally and now it is just that the same is being propagated outside > > also. Inconsistent styling of "Root Port", "root port". Spec uses "CLKREQ#". > > Signed-off-by: Vidya Sagar > > Signed-off-by: Manikanta Maddireddy > Reviewed-by: Vidya Sagar A Reviewed-by tag here seems a little weird since you're the source of the patch. I'm not sure what that would mean.