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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2FA16C35242 for ; Wed, 12 Feb 2020 02:11:38 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id EFEBB206DB for ; Wed, 12 Feb 2020 02:11:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ck/wdwa/"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=google.com header.i=@google.com header.b="wUxk6Sy9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EFEBB206DB Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=bC+grmJPfDgadLtm3+dF0KIL4lborCMSf1aUldnpw2M=; b=ck/wdwa/0/evWe WpHYIG+ZxekjvECUVhd1uoBWgyi+K7YJw9s5UjoTtyaUx4ffBcGDOvhaOPbqFsWZDoa6ccqIxfMTv 79rVqB/Fsdp15/0z/bYxQLdtVTWCvLBfvl1S45lGJB8pG6o10I32e4FhHTWfr58rB1lCFkEl73IWN UG9chJwdNU8HXesMByC+eZF1YGYztUHSRqTbU54xHpLDhuhCGErc+d+sJ2msDY87Ih5oLwC5LibhR a+wOgREqNIeOdutqtIPlfamOy//BqI8QUX+DVsuZeZIM6yAEVcPFyLQ9rdsHwi6j12zH/1fPWPPTw jf16KGC2FW+9s46/A5lQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1j1hUv-00052n-Jd; Wed, 12 Feb 2020 02:11:29 +0000 Received: from mail-ot1-x344.google.com ([2607:f8b0:4864:20::344]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1j1hUm-0004uz-C2 for linux-mediatek@lists.infradead.org; Wed, 12 Feb 2020 02:11:22 +0000 Received: by mail-ot1-x344.google.com with SMTP id j20so392224otq.3 for ; Tue, 11 Feb 2020 18:11:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=n6k/Lbub/n1jxmtDamXfDiU39sk3ANWZWTNVfSZ9e5g=; b=wUxk6Sy9q6qoyjX1z79P+a13uxDl7LnfZY8mNFGDgLHAlzg+XIha1ypLspjBiq7hGA HscwnVJCrLtXWufw1he5v8VfT3HhFn4FyHWnUeTsvsjxPaEAAXBiVH0y2bC/U+NCpyPW 0BtVAPLHJwtrtf3dif65ZmZBB4BUJJNeT61X2XptZj0kCPVjl86sk8jl0uxD4TNa040Y iedDOzlawJRkS23dZ4HPD5Tv83JGGozqICZ559cUnrRv1Za8W1K53jibHXYJ97fH0ckR IF7Z9sw+FkJ1KG/xqorkkIHoNWCYYP0GScu1biUAByDXEN7ff8+g+wya90Fu0XzcpdDT 2g+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=n6k/Lbub/n1jxmtDamXfDiU39sk3ANWZWTNVfSZ9e5g=; b=cPYeHDc/obNaYMguJbN7aS/nIhqpthkDb+9eObw+Q//N5IQ1v0mEEPeW0H7JY2efMP xAEYdRoKa5DEoPGBCMvUovdaCtP4kOs1Yj23wwECI/heluMu0OlMTZx34h0wOvlYnSCd dfjGvoE196t5FMeq5xh1zWaaVP4KCxtr4MljfmApxjwQdy45pG5eRQF08t8NAcbv8uur Xzm98u+sFZm0lWqa/YyQq3O5WMUVVpBWYi36rOfMgkh0xFwZ454FD55IlrLnMYThsy9m 46IBMyrtIs3+Kju7gN7gUMn6iMbCxK146gsj10yvF9GYiHPIYGosAA0mck9GL3CvefXn +sNg== X-Gm-Message-State: APjAAAWwD+IGDr7YZUIbrzbtdhhoQmbqqs6he0o1U/keqgyGzcv+B7zi VWZW2wwDl4NOvRHMVHxa5xlR1seb33uqjw+KdUKPmw== X-Google-Smtp-Source: APXvYqx9WyDPh84T/dWz0V7MAkV6Fu38Ls7r23WUTJHuOaZMt9M7Cqkp1o3QjcNUD57URwJnbkv4nhKPOxGIjSTARy8= X-Received: by 2002:a05:6830:22ee:: with SMTP id t14mr7441403otc.236.1581473478420; Tue, 11 Feb 2020 18:11:18 -0800 (PST) MIME-Version: 1.0 References: <20200207052627.130118-1-drinkcat@chromium.org> <20200207052627.130118-6-drinkcat@chromium.org> In-Reply-To: From: Saravana Kannan Date: Tue, 11 Feb 2020 18:10:42 -0800 Message-ID: Subject: Re: [PATCH v4 5/7] drm/panfrost: Add support for multiple power domains To: Rob Herring X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200211_181120_442248_FFB30368 X-CRM114-Status: GOOD ( 34.96 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" , Ulf Hansson , Nicolas Boichat , Tomeu Vizoso , Greg Kroah-Hartman , David Airlie , "linux-kernel@vger.kernel.org" , Liam Girdwood , dri-devel , Steven Price , Mark Brown , "moderated list:ARM/Mediatek SoC support" , Alyssa Rosenzweig , Daniel Vetter , Hsin-Yi Wang , Matthias Brugger , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Tue, Feb 11, 2020 at 5:58 PM Rob Herring wrote: > > On Tue, Feb 11, 2020 at 2:09 PM Saravana Kannan wrote: > > > > On Tue, Feb 11, 2020 at 11:44 AM Rob Herring wrote: > > > > > > +Saravana > > > > > > On Thu, Feb 6, 2020 at 11:27 PM Nicolas Boichat wrote: > > > > > > > > When there is a single power domain per device, the core will > > > > ensure the power domain is switched on (so it is technically > > > > equivalent to having not power domain specified at all). > > > > > > > > However, when there are multiple domains, as in MT8183 Bifrost > > > > GPU, we need to handle them in driver code. > > > > > > > > Signed-off-by: Nicolas Boichat > > > > > > > > --- > > > > > > > > The downstream driver we use on chromeos-4.19 currently uses 2 > > > > additional devices in device tree to accomodate for this [1], but > > > > I believe this solution is cleaner. > > > > > > > > [1] https://chromium.googlesource.com/chromiumos/third_party/kernel/+/refs/heads/chromeos-4.19/drivers/gpu/arm/midgard/platform/mediatek/mali_kbase_runtime_pm.c#31 > > > > > > > > v4: > > > > - Match the exact power domain names as specified in the compatible > > > > struct, instead of just matching the number of power domains. > > > > [Review: Ulf Hansson] > > > > - Dropped print and reordered function [Review: Steven Price] > > > > - nits: Run through latest version of checkpatch: > > > > - Use WARN instead of BUG_ON. > > > > - Drop braces for single expression if block. > > > > v3: > > > > - Use the compatible matching data to specify the number of power > > > > domains. Note that setting 0 or 1 in num_pm_domains is equivalent > > > > as the core will handle these 2 cases in the exact same way > > > > (automatically, without driver intervention), and there should > > > > be no adverse consequence in this case (the concern is about > > > > switching on only some power domains and not others). > > > > > > > > drivers/gpu/drm/panfrost/panfrost_device.c | 97 ++++++++++++++++++++-- > > > > drivers/gpu/drm/panfrost/panfrost_device.h | 11 +++ > > > > drivers/gpu/drm/panfrost/panfrost_drv.c | 2 + > > > > 3 files changed, 102 insertions(+), 8 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/panfrost/panfrost_device.c b/drivers/gpu/drm/panfrost/panfrost_device.c > > > > index 3720d50f6d9f965..8136babd3ba9935 100644 > > > > --- a/drivers/gpu/drm/panfrost/panfrost_device.c > > > > +++ b/drivers/gpu/drm/panfrost/panfrost_device.c > > > > @@ -5,6 +5,7 @@ > > > > #include > > > > #include > > > > #include > > > > +#include > > > > #include > > > > > > > > #include "panfrost_device.h" > > > > @@ -120,6 +121,79 @@ static void panfrost_regulator_fini(struct panfrost_device *pfdev) > > > > pfdev->regulators); > > > > } > > > > > > > > +static void panfrost_pm_domain_fini(struct panfrost_device *pfdev) > > > > +{ > > > > + int i; > > > > + > > > > + for (i = 0; i < ARRAY_SIZE(pfdev->pm_domain_devs); i++) { > > > > + if (!pfdev->pm_domain_devs[i]) > > > > + break; > > > > + > > > > + if (pfdev->pm_domain_links[i]) > > > > + device_link_del(pfdev->pm_domain_links[i]); > > > > + > > > > + dev_pm_domain_detach(pfdev->pm_domain_devs[i], true); > > > > + } > > > > +} > > > > + > > > > +static int panfrost_pm_domain_init(struct panfrost_device *pfdev) > > > > +{ > > > > + int err; > > > > + int i, num_domains; > > > > + > > > > + num_domains = of_count_phandle_with_args(pfdev->dev->of_node, > > > > + "power-domains", > > > > + "#power-domain-cells"); > > > > + > > > > + /* > > > > + * Single domain is handled by the core, and, if only a single power > > > > + * the power domain is requested, the property is optional. > > > > + */ > > > > + if (num_domains < 2 && pfdev->comp->num_pm_domains < 2) > > > > + return 0; > > > > + > > > > + if (num_domains != pfdev->comp->num_pm_domains) { > > > > + dev_err(pfdev->dev, > > > > + "Incorrect number of power domains: %d provided, %d needed\n", > > > > + num_domains, pfdev->comp->num_pm_domains); > > > > + return -EINVAL; > > > > + } > > > > + > > > > + if (WARN(num_domains > ARRAY_SIZE(pfdev->pm_domain_devs), > > > > + "Too many supplies in compatible structure.\n")) > > > > + return -EINVAL; > > > > + > > > > + for (i = 0; i < num_domains; i++) { > > > > + pfdev->pm_domain_devs[i] = > > > > + dev_pm_domain_attach_by_name(pfdev->dev, > > > > + pfdev->comp->pm_domain_names[i]); > > > > + if (IS_ERR_OR_NULL(pfdev->pm_domain_devs[i])) { > > > > + err = PTR_ERR(pfdev->pm_domain_devs[i]) ? : -ENODATA; > > > > + pfdev->pm_domain_devs[i] = NULL; > > > > + dev_err(pfdev->dev, > > > > + "failed to get pm-domain %s(%d): %d\n", > > > > + pfdev->comp->pm_domain_names[i], i, err); > > > > + goto err; > > > > + } > > > > + > > > > + pfdev->pm_domain_links[i] = device_link_add(pfdev->dev, > > > > + pfdev->pm_domain_devs[i], DL_FLAG_PM_RUNTIME | > > > > + DL_FLAG_STATELESS | DL_FLAG_RPM_ACTIVE); > > > > > > We're in the process of adding device links based on DT properties. > > > Shouldn't we add power domains to that? See drivers/of/property.c for > > > what's handled. > > > > Rob, > > > > drivers/of/property.c doesn't enable the RPM_ACTIVE AND PM_RUNTIME > > flags. Wanted to start off conservative. > > I worry that you can't add it later without potentially breaking platforms. > > I haven't checked, but I assume these flags make runtime PM honor > device links? That seems like the more conservative option (more > reasons why a device can't suspend). Conservative as in, if of_devlink adds the RPM_ACTIVE flag, the drivers can't remove it. > > But adding command line ops > > to change the default flags shouldn't be difficult. But before I do > > that, I want to change of_devlink to > > fw_devlink=. May be I can extend that to > > "disabled, permissive, suspend, runtime". > > I think any command line option should be debug primarily. It's kind > of a big hammer. It is a big hammer. But it's better than disabling of_devlink altogether. There is always going to be weird hardware that won't work with of_devlink if all the device link flags are set. They'll need some fix up of drivers and/or clean up of DT. And having different of_devlink command line options would at least let those hardware to run with as much of_devlink enabled as possible while working to get more fixes into the kernel. That way, we can make sure we don't regress further while trying to improve the support. > Can drivers adjust the flags themselves? Just modify the flags rather > than trying to create new links? They can, but only in an additive manner. And the way to do it would be to add a device link like usual and the framework takes care of combining the flags. That's why I don't set most of the flags by default. -Saravana _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek