From patchwork Tue Jan 25 14:15:47 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxime Ripard X-Patchwork-Id: 12723834 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 063C5C433F5 for ; Tue, 25 Jan 2022 14:16:25 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 150C610E609; Tue, 25 Jan 2022 14:16:24 +0000 (UTC) Received: from out1-smtp.messagingengine.com (out1-smtp.messagingengine.com [66.111.4.25]) by gabe.freedesktop.org (Postfix) with ESMTPS id E9DFD10E500 for ; Tue, 25 Jan 2022 14:16:10 +0000 (UTC) Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id 536115C011C; Tue, 25 Jan 2022 09:16:10 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute4.internal (MEProxy); Tue, 25 Jan 2022 09:16:10 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cerno.tech; h=cc :cc:content-transfer-encoding:date:date:from:from:in-reply-to :in-reply-to:message-id:mime-version:references:reply-to:sender :subject:subject:to:to; s=fm1; bh=wkyNpQaqe/5yqepEtzW1vHU0+7nQsE z2kObpQxckMxk=; b=OPiAbWEHEEuQZcvJ3cMKeWIJz9MEvoOsekJRy31/2TrIAO myFc+RFM6FqP7bVvv6jh/DTcLvhvPxR1gXWkPexyOAM8lw8Riu2iLtt/cuPJExSD fCqjYVsJDMlAUoiI4tm/NlfGEZ/DkNJgBDPB6GdtpugRnB7WMrvNWwuNeRiQZ0YQ I5xxS1WvZfwTUHI5yIjGDTRr7XgBIZr7lWqddrv+Gq1KTyhgHFXRewXaQO/6PoJS P7z0fwv1PUmGX0vMCdAd5Z+5o99Cw9OjKcNrW/JQfLtL//Hls5xhiqHf2H0SfmUO r21hHRNxgh6k/xEZ3P64GERGbTHqFy9AGI8bj2Bw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding:date:date :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:sender:subject:subject:to:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=wkyNpQ aqe/5yqepEtzW1vHU0+7nQsEz2kObpQxckMxk=; b=TTs9K+69Lh8MoEwc75VF+I UXk1rPeqdQdVOaPxYZPwoaTj5+3mm1Dlbea0Tn0jW4bIWB5Rd/jdYesdyXUZOADY VliCM86hFx+pcS5CqfozRbjYwOewKNgKYNeTjmf8ttr+QoF8MwtFEAd97oGbYWUY wtxbXAlYEQ9DRv7Bfzze/sbzuyR5eGES8oUSmiapfWY9Y7IjqBADZhcpmM7cF+LD x0iN/L5FdpSUX2pb1UCrlPtljCG6FRWOAIZhFS0rDrNT2ONtZEDysHETpcg6w3U9 fPK3up0fFXgPFSpdfz3xm6TqEXsx9i+49pRoxZRzVWGaU5wUTQPGhaChx+tKaHzA == X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvvddrvdelgdeitdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkofgjfhgggfestdekredtredttdenucfhrhhomhepofgrgihimhgv ucftihhprghrugcuoehmrgigihhmvgestggvrhhnohdrthgvtghhqeenucggtffrrghtth gvrhhnpedvkeelveefffekjefhffeuleetleefudeifeehuddugffghffhffehveevheeh vdenucevlhhushhtvghrufhiiigvpedunecurfgrrhgrmhepmhgrihhlfhhrohhmpehmrg igihhmvgestggvrhhnohdrthgvtghh X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Tue, 25 Jan 2022 09:16:09 -0500 (EST) From: Maxime Ripard To: Mike Turquette , Stephen Boyd Subject: [PATCH v4 08/10] clk: bcm: rpi: Run some clocks at the minimum rate allowed Date: Tue, 25 Jan 2022 15:15:47 +0100 Message-Id: <20220125141549.747889-9-maxime@cerno.tech> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220125141549.747889-1-maxime@cerno.tech> References: <20220125141549.747889-1-maxime@cerno.tech> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Dom Cobley , Tim Gover , Dave Stevenson , dri-devel@lists.freedesktop.org, linux-clk@vger.kernel.org, Maxime Ripard , Phil Elwell Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" The core clock and M2MC clocks are shared between some devices (Unicam controllers and the HVS, and the HDMI controllers, respectively) that will have various, varying, requirements depending on their current work load. Since those loads can require a fairly high clock rate in extreme conditions (up to ~600MHz), we can end up running those clocks at their maximum frequency even though we no longer require such a high rate. Fortunately, those devices don't require an exact rate but a minimum rate, and all the drivers are using clk_set_min_rate. Thus, we can just rely on the fact that the clk_request minimum (which is the aggregated minimum of all the clock users) is what we want at all times. Signed-off-by: Maxime Ripard --- drivers/clk/bcm/clk-raspberrypi.c | 37 +++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/drivers/clk/bcm/clk-raspberrypi.c b/drivers/clk/bcm/clk-raspberrypi.c index c879f2e9a4a7..9d09621549b9 100644 --- a/drivers/clk/bcm/clk-raspberrypi.c +++ b/drivers/clk/bcm/clk-raspberrypi.c @@ -77,6 +77,7 @@ struct raspberrypi_clk_variant { bool export; char *clkdev; unsigned long min_rate; + bool minimize; }; static struct raspberrypi_clk_variant @@ -87,6 +88,18 @@ raspberrypi_clk_variants[RPI_FIRMWARE_NUM_CLK_ID] = { }, [RPI_FIRMWARE_CORE_CLK_ID] = { .export = true, + + /* + * The clock is shared between the HVS and the CSI + * controllers, on the BCM2711 and will change depending + * on the pixels composited on the HVS and the capture + * resolution on Unicam. + * + * Since the rate can get quite large, and we need to + * coordinate between both driver instances, let's + * always use the minimum the drivers will let us. + */ + .minimize = true, }, [RPI_FIRMWARE_M2MC_CLK_ID] = { .export = true, @@ -102,6 +115,16 @@ raspberrypi_clk_variants[RPI_FIRMWARE_NUM_CLK_ID] = { * in this situation. */ .min_rate = 120000000, + + /* + * The clock is shared between the two HDMI controllers + * on the BCM2711 and will change depending on the + * resolution output on each. Since the rate can get + * quite large, and we need to coordinate between both + * driver instances, let's always use the minimum the + * drivers will let us. + */ + .minimize = true, }, [RPI_FIRMWARE_V3D_CLK_ID] = { .export = true, @@ -206,12 +229,26 @@ static int raspberrypi_fw_set_rate(struct clk_hw *hw, unsigned long rate, static int raspberrypi_fw_dumb_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { + struct raspberrypi_clk_data *data = + container_of(hw, struct raspberrypi_clk_data, hw); + struct raspberrypi_clk_variant *variant = data->variant; + /* * The firmware will do the rounding but that isn't part of * the interface with the firmware, so we just do our best * here. */ + req->rate = clamp(req->rate, req->min_rate, req->max_rate); + + /* + * We want to aggressively reduce the clock rate here, so let's + * just ignore the requested rate and return the bare minimum + * rate we can get away with. + */ + if (variant->minimize && req->min_rate > 0) + req->rate = req->min_rate; + return 0; }