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 1158225CC7A; Mon, 14 Jul 2025 15:12:22 +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=1752505942; cv=none; b=qXfzjNWPjZ4QSqzkYLqHKT1X/XqQiYGljKBOJWLb/2TmAe9ghYYUZ2+Z0GjsxfFv+lUgZbDGvZVIjRc6uRrBt5iDgayK7zrlhv9yBt3mNdTGt/HcMDauhq38UsaE0UUDhs5y5itx/Ff8VMd6TjlDhHc3l6FHV7mHM+0WyWltl3Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752505942; c=relaxed/simple; bh=mXB87Bpc3vfmGJ3xVQnf0jSRexpExNYLcwlFgBP5krk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=dmOgPpM6vrI0dR6njEVgryM5Szy33jeOL8WVXEUZ1yOOnnUMisqymBs5OQSihgV7C+vDerS0JMdMVZIOFoGSAg9gyg4IDrUZedwNNQ3L00puNTk6u6dbNtQyDFtcHLScwXPsJ6+cp7xdWeFxFzN79M0sPzOBcI9G1ZXsqLlkF7U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tj/H0Noq; 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="tj/H0Noq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F1BA4C4CEED; Mon, 14 Jul 2025 15:12:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1752505941; bh=mXB87Bpc3vfmGJ3xVQnf0jSRexpExNYLcwlFgBP5krk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tj/H0NoqvGLmDRq2iwlyOPEE0dpYcGJaPGpn6tdKz68CeIpoluy6/VJQqcLSPCLdg t2AmcHR216SD5vFfy+XvAI/hLiHuRhBK1HSgzafBx9vJ/1CTqobJbo7hgf6QDM/zDW MU+VL0tJ0IeuOIwxp+dEtaTgIg8wl21ALR+lMmJW8DfZib02JL8ar2NVqFbEVnbdSL /dmbMT4B6YbFOEugb47P2/ioekwZcBYS+OQ0EqtLFJTDYxlRvWEAUhUkJomL3R+P79 dw4ZSAc8zeI4MWUSgxQbhmo89zPOtFjzts7nyn5Vx9CSEWuZHl+xLQWevxszvWGE6c NacDlA62rUTbg== Date: Mon, 14 Jul 2025 16:12:16 +0100 From: Will Deacon To: Nick Chan Cc: Mark Rutland , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Catalin Marinas , Janne Grunau , Alyssa Rosenzweig , Neal Gompa , Sven Peter , Marc Zyngier , linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, devicetree@vger.kernel.org, asahi@lists.linux.dev, linux-kernel@vger.kernel.org, Krzysztof Kozlowski Subject: Re: [PATCH RESEND v7 00/21] drivers/perf: apple_m1: Add Apple A7-A11, T2 SoC support Message-ID: References: <20250616-apple-cpmu-v7-0-df2778a44d5c@gmail.com> Precedence: bulk X-Mailing-List: devicetree@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: <20250616-apple-cpmu-v7-0-df2778a44d5c@gmail.com> On Mon, Jun 16, 2025 at 09:31:49AM +0800, Nick Chan wrote: > This series adds support for the CPU PMU in the older Apple A7-A11, T2 > SoCs. These PMUs may have a different event layout, less counters, or > deliver their interrupts via IRQ instead of a FIQ. Since some of those > older SoCs support 32-bit EL0, counting for 32-bit EL0 also need to > be enabled by the driver where applicable. > > Patch 1 adds the DT bindings. > Patch 2-7 prepares the driver to allow adding support for those > older SoCs. Modulo my nits, the patches look alright to this point... > Patch 8-12 adds support for the older SoCs. ... but I'm not sure if anybody actually cares about these older SoCs and, even if they do, what the state of the rest of Linux is on those parts. I recall horror stories about the OS being quietly migrated between CPUs with incompatible features, at which point I think we have to question whether we actually care about supporting this hardware. On the other hand, if it all works swimmingly and it's just the PMU driver that needs updating, then I could get on board with it. Will