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 48A0353A7; Fri, 7 Feb 2025 10:41:34 +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=1738924895; cv=none; b=MiFhI0kPnfnH/FRfdBxFNN3WYMaSnOmgMx70TCtS3jzZu/8cZLitEFjcMPm/1sPd2ZWhnPk6y5Kj74PHqh2qXdkR8lCZVBuYNXKh/b8rdjpXS0OCML14vJqcb7Ihdx0o8v/CCnQpn0kXMRpR9lZpgC/Ik/30PmXSyieG4AUfk/E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738924895; c=relaxed/simple; bh=UzsjoUCqhTOFiLpomAhh9OUmFU4xJr7T+OHaniS6+Js=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SKzW2ULZHgmlvXcESYkSuKP8BCQrSXXx0/iRhXigOKIKLDcXGECh+4jMnCtVJ0kf2ZHtQxA49WwxD5w/Iy9C35TB/siDesjKaLFd0YgUy4tTBUsk8i9HOlieIZsUnNEXSywf9dJtZycd7c8i6gp8aDs1y+T3NCKlvjAxP5qN/2U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Q0XrUub7; 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="Q0XrUub7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0917CC4CED1; Fri, 7 Feb 2025 10:41:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738924893; bh=UzsjoUCqhTOFiLpomAhh9OUmFU4xJr7T+OHaniS6+Js=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Q0XrUub7ZzUUrFOvSlVSs1xNDC5AFx6d6VmTXMC8qZRuQmLm6jCAns/4Aga4JvE0O 09WhXvfwuv5SdTdSaHryWRPh9sGaHjKS+3GbUe/XdkJJnV+PXqSCAI4R+CZQkeWA6D gCZ8aP3U/Z6ho77enkGuwrk5HgMpfymKoPa2HmxYAG/d5YQIkEQoB9KlxfYN6Gbd5z ZPXMB5SACHoCEmf568E/dC9GKli/t/XrtYoDuhMPe9d2FDol24g3GSel6tkUoHgGVd Ay+QA/9QvDeI5Tft4bsM9JGhDgF5Ab7Zw+WxEndJ8hurCZ/i2EOtfRaIBbE4+zKmVm fZlktHlXq416Q== Date: Fri, 7 Feb 2025 11:41:28 +0100 From: Niklas Cassel To: Thierry Reding Cc: Manivannan Sadhasivam , Vidya Sagar , lpieralisi@kernel.org, kw@linux.com, robh@kernel.org, bhelgaas@google.com, quic_schintav@quicinc.com, johan+linaro@kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, jonathanh@nvidia.com, kthota@nvidia.com, mmaddireddy@nvidia.com, sagar.tv@gmail.com Subject: Re: [PATCH V1] PCI: tegra194: Add support for PCIe RC & EP in Tegra234 Platforms Message-ID: References: <20250128044244.2766334-1-vidyas@nvidia.com> <20250203165932.72kezmi3dtqpytvg@thinkpad> Precedence: bulk X-Mailing-List: linux-kernel@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: On Tue, Feb 04, 2025 at 06:19:51PM +0100, Thierry Reding wrote: > On Mon, Feb 03, 2025 at 10:29:32PM +0530, Manivannan Sadhasivam wrote: > > On Tue, Jan 28, 2025 at 01:04:32PM +0100, Niklas Cassel wrote: > > > Hello Vidya, > > > > > > On Tue, Jan 28, 2025 at 10:12:44AM +0530, Vidya Sagar wrote: > > > > Add PCIe RC & EP support for Tegra234 Platforms. > > > > > > The commit log does leave quite a few questions unanswered. > > > > > > Since you are just updating the Kconfig and nothing else: > > > Does the DT binding already have support for the Tegra234 SoC? > > > Does the driver already have support for the Tegra234 SoC? > > > > > > Looking at the DT binding and driver, the answer to both questions > > > is yes. (This should have been in the commit message IMO.) > > > > > > > > > But that leads me to the question, since there is support for Tegra234 > > > SoC in the driver, does this means that this fixes a regression, e.g. > > > the Kconfig ARCH_TEGRA_234_SOC was added after the driver support in > > > this driver was added. In this case, you should have a Fixes: tag that > > > points to the commit that added ARCH_TEGRA_234_SOC. > > > > > > Or has the the driver support for Tegra234 been "dead-code" since it > > > was originally added? (Because without this patch, no one can have > > > tested it, at least not without COMPILE_TEST.) > > > In this case, you should add: > > > Fixes: a54e19073718 ("PCI: tegra194: Add Tegra234 PCIe support") > > > > > > > TBH, I don't like muddling with Kconfig like this. Ideally, the driver should > > just depend on ARCH_TEGRA || COMPILE_TEST and the driver should be selected by > > the relevant defconfig. > > ARCH_TEGRA is a symbol that exists both on 32-bit and 64-bit ARM. This > driver is completely useless on 32-bit ARM and only used on a very small > subset of 64-bit ARM devices. It doesn't make sense to be able to enable > this if you want to build a kernel for say Tegra210. Well, if you look in drivers/pci/controller/dwc/Kconfig there are quite a few drivers that does: depends on ARM64 or ARM and then a ARCH_ something. I don't see why you can't do depends on (ARCH_TEGRA && ARM64) || COMPILE_TEST Kind regards, Niklas