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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDEA3C6FD18 for ; Wed, 29 Mar 2023 13:10:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229904AbjC2NKy (ORCPT ); Wed, 29 Mar 2023 09:10:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229687AbjC2NKw (ORCPT ); Wed, 29 Mar 2023 09:10:52 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [46.235.227.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F878B3 for ; Wed, 29 Mar 2023 06:10:51 -0700 (PDT) Received: from [192.168.1.100] (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) (Authenticated sender: kholk11) by madras.collabora.co.uk (Postfix) with ESMTPSA id 51639660316A; Wed, 29 Mar 2023 14:10:49 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1680095449; bh=zVF05hk59CfKnrDedjRCcIbn2rciK8fjt91K0SYGKs0=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=kLIK6vjSO6D3vnJU2Y7GEV43CCe5hMhUPU3FsmrbVWeNYe3O8t24DRNXUTqQizhdU ZAlqnoByiPIvJX30W/jOXgt2jHTvDGSgVW+60vqcRDFan1dg4/z4wjb7UqK8sOAec2 ryVNiwSiqt3/NQqpwhw0lakQN4VnwMadeDs0S385Xv4170Tvp+efdDBwvPVuv3U5FD NLixSbFUA8U5m+bxYm/cgN8LDSRylYG9jtYyYGzqW/dnoIKRq2VOnZizqUsYJLq6Et j49ucpc/ut6t/bYR8lRX4/L7LpvF58zHTqtlsfn1V9+WAHnqvJJnIcgkid6lii4SP6 2H/zbEDSiZOIQ== Message-ID: <75a890d1-b3b9-0316-749b-fb2bf80c3176@collabora.com> Date: Wed, 29 Mar 2023 15:10:46 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH] clocksource/drivers/timer-mediatek: Split out CPUXGPT timers Content-Language: en-US To: =?UTF-8?B?V2FsdGVyIENoYW5nICjlvLXntq3lk7Ip?= , "daniel.lezcano@linaro.org" Cc: "linux-kernel@vger.kernel.org" , "linux-mediatek@lists.infradead.org" , "tglx@linutronix.de" , wsd_upstream , "kernel@collabora.com" , =?UTF-8?B?Q2h1bi1IdW5nIFd1ICjlt6vpp7/lro8p?= , "linux-arm-kernel@lists.infradead.org" , =?UTF-8?B?U3RhbmxleSBDaHUgKOacseWOn+mZnik=?= , =?UTF-8?B?RnJlZGR5IEhzaW4gKOi+m+aBkuixkCk=?= , "matthias.bgg@gmail.com" References: <20230309103913.116775-1-angelogioacchino.delregno@collabora.com> From: AngeloGioacchino Del Regno In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 29/03/23 09:51, Walter Chang (張維哲) ha scritto: > On Thu, 2023-03-09 at 11:39 +0100, AngeloGioacchino Del Regno wrote: >> On MediaTek platforms, CPUXGPT is the source for the AArch64 System >> Timer, read through CNTVCT_EL0. >> >> The handling for starting this timer ASAP was introduced in commit >> 327e93cf9a59 ("clocksource/drivers/timer-mediatek: Implement CPUXGPT >> timers") >> which description also contains an important full explanation of the >> reasons why this driver is necessary and cannot be a module. >> >> In preparation for an eventual conversion of timer-mediatek to a >> platform_driver that would be possibly built as a module, split out >> the CPUXGPT timers driver to a new timer-mediatek-cpux.c driver. >> >> This commit brings no functional changes. >> >> Signed-off-by: AngeloGioacchino Del Regno < >> angelogioacchino.delregno@collabora.com> >> --- >> >> Note: I've added a mention to the commit that is introducing CPUXGPT >> because it contains a broad explanation about why this is needed and >> why it is mandatory to have it as built-in and initialized as early >> as possible. This is mostly because this question was asked multiple >> times and I've been pointing people to that commit to explain it all. >> >> This commit was made because of a discussion about the impossibility >> to convert timer-mediatek to a module: even though that's definitely >> not easy at all, this will make sure that whatever cannot (ever) be >> built as module goes out of that driver. >> >> I tried to tackle a timer-mediatek conversion to platform_driver as >> well, but I don't currently have the required bandwidth to do so: >> as a first step I moved that, so I'm pushing this commit as to try >> to reduce duplicated work. >> >> This commit was tested on MT6795 Sony Xperia M5. ..snip.. >> @@ -452,4 +339,3 @@ static int __init mtk_gpt_init(struct device_node >> *node) >> } >> TIMER_OF_DECLARE(mtk_mt6577, "mediatek,mt6577-timer", mtk_gpt_init); >> TIMER_OF_DECLARE(mtk_mt6765, "mediatek,mt6765-timer", >> mtk_syst_init); >> -TIMER_OF_DECLARE(mtk_mt6795, "mediatek,mt6795-systimer", >> mtk_cpux_init); > > This patch looks good to me. Thanks for assisting us in spliting out > the CPUX driver. > Hello Walter, thanks for checking this patch. If you have actually reviewed this one, you could help the maintainers to know by releasing your Reviewed-by tag on this patch. Regards, Angelo