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 6788EC4332F for ; Mon, 30 Oct 2023 14:57:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233548AbjJ3O5H (ORCPT ); Mon, 30 Oct 2023 10:57:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233594AbjJ3O5A (ORCPT ); Mon, 30 Oct 2023 10:57:00 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6D47810D for ; Mon, 30 Oct 2023 07:56:57 -0700 (PDT) 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 BD8DC1007; Mon, 30 Oct 2023 07:57:38 -0700 (PDT) Received: from [10.57.36.72] (unknown [10.57.36.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2817C3F64C; Mon, 30 Oct 2023 07:56:54 -0700 (PDT) Message-ID: <2b553f07-71d0-4d06-8f60-7cd8f29d78e1@arm.com> Date: Mon, 30 Oct 2023 14:57:03 +0000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/4] drm/panfrost: Implement ability to turn on/off regulators in suspend Content-Language: en-GB To: AngeloGioacchino Del Regno , boris.brezillon@collabora.com Cc: robh@kernel.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, daniel@ffwll.ch, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, wenst@chromium.org, kernel@collabora.com References: <20231030132257.85379-1-angelogioacchino.delregno@collabora.com> <20231030132257.85379-4-angelogioacchino.delregno@collabora.com> From: Steven Price In-Reply-To: <20231030132257.85379-4-angelogioacchino.delregno@collabora.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/10/2023 13:22, AngeloGioacchino Del Regno wrote: > Some platforms/SoCs can power off the GPU entirely by completely cutting > off power, greatly enhancing battery time during system suspend: add a > new pm_feature GPU_PM_VREG_OFF to allow turning off the GPU regulators > during full suspend only on selected platforms. > > Signed-off-by: AngeloGioacchino Del Regno > --- > drivers/gpu/drm/panfrost/panfrost_device.c | 19 ++++++++++++++++++- > drivers/gpu/drm/panfrost/panfrost_device.h | 2 ++ > 2 files changed, 20 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c > index 2022ed76a620..51b22eb0971d 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_device.c > +++ b/drivers/gpu/drm/panfrost/panfrost_device.c > @@ -431,10 +431,21 @@ static int panfrost_device_resume(struct device *dev) > struct panfrost_device *pfdev = dev_get_drvdata(dev); > int ret; > > + if (pfdev->comp->pm_features & BIT(GPU_PM_VREG_OFF)) { > + unsigned long freq = pfdev->pfdevfreq.fast_rate; > + struct dev_pm_opp *opp; > + > + opp = dev_pm_opp_find_freq_ceil(dev, &freq); > + if (IS_ERR(opp)) > + return PTR_ERR(opp); > + dev_pm_opp_put(opp); > + dev_pm_opp_set_opp(dev, opp); These lines look the wrong way round - surely we want to hang onto the reference until the set_opp call is made? Steve > + } > + > if (pfdev->comp->pm_features & BIT(GPU_PM_CLK_DIS)) { > ret = clk_enable(pfdev->clock); > if (ret) > - return ret; > + goto err_clk; > > if (pfdev->bus_clock) { > ret = clk_enable(pfdev->bus_clock); > @@ -455,6 +466,9 @@ static int panfrost_device_resume(struct device *dev) > err_bus_clk: > if (pfdev->comp->pm_features & BIT(GPU_PM_CLK_DIS)) > clk_disable(pfdev->clock); > +err_clk: > + if (pfdev->comp->pm_features & BIT(GPU_PM_VREG_OFF)) > + dev_pm_opp_set_opp(dev, NULL); > return ret; > } > > @@ -474,6 +488,9 @@ static int panfrost_device_suspend(struct device *dev) > clk_disable(pfdev->bus_clock); > } > > + if (pfdev->comp->pm_features & BIT(GPU_PM_VREG_OFF)) > + dev_pm_opp_set_opp(dev, NULL); > + > return 0; > } > > diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h > index d7f179eb8ea3..0fc558db6bfd 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_device.h > +++ b/drivers/gpu/drm/panfrost/panfrost_device.h > @@ -28,9 +28,11 @@ struct panfrost_perfcnt; > /** > * enum panfrost_gpu_pm - Supported kernel power management features > * @GPU_PM_CLK_DIS: Allow disabling clocks during system suspend > + * @GPU_PM_VREG_OFF: Allow turning off regulators during system suspend > */ > enum panfrost_gpu_pm { > GPU_PM_CLK_DIS, > + GPU_PM_VREG_OFF, > }; > > struct panfrost_features {