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 77FC6C3DA6E for ; Thu, 28 Dec 2023 11:54:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=47yNq+nn5shkQ60gmx5ig3mduxZVzlQHY1hX3W3vTUo=; b=p9ceSOR+/KfSRm V1u3ZiHtErZsFkP1nO3l5XoV1cmCpxi25ZLJHQ/fhuscUJj50Yw3no/DFTS4jxCPYrDZVwc3Q5CRK cvHDAF3h1eLPeOHsiMThzA6Kulgh5QIg4FNf6oEYZtxIyCMDWbnbdgntYCV/sVgaWqMolWHeLkZoY hRuUK061fiPX9dow5YrkHETsqyfL+W3HVfdWnhLR62+SP40KsMM9Sg9nAf+Jb5hS1KvBde99YoZDK AKkBW7foHUFuISqlA3yHu2EFwqYMZZjACvxC0O0Xq6kmdEgs6PuUZb5OqVGgudP0MrEj88ct9DE6k zwuhV6nVbikp90ErqdsQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rIoxk-00Gnrn-1N; Thu, 28 Dec 2023 11:54:08 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rIoxh-00GnrR-0M for linux-arm-kernel@lists.infradead.org; Thu, 28 Dec 2023 11:54:06 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2A2072F4; Thu, 28 Dec 2023 03:54:49 -0800 (PST) Received: from bogus (unknown [10.57.74.54]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 71CFC3F5A1; Thu, 28 Dec 2023 03:54:01 -0800 (PST) Date: Thu, 28 Dec 2023 11:50:53 +0000 From: Sudeep Holla To: Konrad Dybcio Cc: Mark Rutland , Sudeep Holla , Lorenzo Pieralisi , Marijn Suijten , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Bjorn Andersson Subject: Re: [PATCH 2/2] firmware/psci: Set pm_set_resume/suspend_via_firmware() on qcom Message-ID: <20231228115053.zlypgc5uxxvghi4a@bogus> References: <20231227-topic-psci_fw_sus-v1-0-6910add70bf3@linaro.org> <20231227-topic-psci_fw_sus-v1-2-6910add70bf3@linaro.org> <20231228102801.fzaubcjq5thfwgxg@bogus> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231228_035405_198723_64FAE18F X-CRM114-Status: GOOD ( 20.97 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Dec 28, 2023 at 12:47:51PM +0100, Konrad Dybcio wrote: > On 28.12.2023 11:28, Sudeep Holla wrote: > > On Wed, Dec 27, 2023 at 11:15:31PM +0100, Konrad Dybcio wrote: > >> Most Qualcomm platforms implementing PSCI (ab)use CPU_SUSPEND for > >> entering various stages of suspend, across the SoC. These range from a > >> simple WFI to a full-fledged power collapse of the entire chip > >> (mostly, anyway). > >> > >> Some device drivers are curious to know whether "the firmware" (which is > >> often assumed to be ACPI) takes care of suspending or resuming the > >> platform. Set the flag that reports this behavior on the aforementioned > >> chips. > >> > >> Some newer Qualcomm chips ship with firmware that actually advertises > >> PSCI SYSTEM_SUSPEND, so the compatible list should only grow slightly. > >> > > > > NACK, just use suspend-to-idle if SYSTEM_SUSPEND is not advertised. It is > > designed for such platforms especially on x86/ACPI which don't advertise > > Sx states. I see no reason why that doesn't work on ARM platforms as well. > > Not sure if I got the message through well, but the bottom line is, on > Qualcomm platforms the "idle" states aren't actually just "idle" (read: > they're not like S0ix). All but the most shallow ones shut down quite a > chunk of the entire SoC, with the lowest ones being essentially S3 with > power being cut off from the entire chip, except for the memory rail. > No I understood that and S2I is exactly what you need. Have you checked if S2I already works as intended on these platforms ? What extra do you achieve with this hack by advertising fake S2R ? S2I will have less latency compared to S2R and the mem_sleep will be automatically set to S2I if S2R is not supported, so no userspace impact as well. So please let us know what this change provide extra over S2I ? Until then my NACK still stands. -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel