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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 18256C432BE for ; Wed, 4 Aug 2021 22:23:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EDE4D61004 for ; Wed, 4 Aug 2021 22:23:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230236AbhHDWXq (ORCPT ); Wed, 4 Aug 2021 18:23:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233420AbhHDWXq (ORCPT ); Wed, 4 Aug 2021 18:23:46 -0400 Received: from mail-wm1-x333.google.com (mail-wm1-x333.google.com [IPv6:2a00:1450:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E482CC0613D5 for ; Wed, 4 Aug 2021 15:23:31 -0700 (PDT) Received: by mail-wm1-x333.google.com with SMTP id o7-20020a05600c5107b0290257f956e02dso4896886wms.1 for ; Wed, 04 Aug 2021 15:23:31 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=jEthsYo5cmrwocLVz5njVZMxGrlW+toglpTtJsaIK7Q=; b=TMQCCF2AiqRqYKNVsJzmTaCv9ETLG5R6ez+x/GFOxzQEpuUj0eYZsU5tMsplR/wd1a Ihx54UjmrGlgp5lh2XOIDxNOqh9NxkJrCQD7EEIrwN9FqlUoDU51/L4PAJ/ROYIsJLhk fNNTdU7tkKIrkutkxblA1H6kRSqbxYpN8MQkk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=jEthsYo5cmrwocLVz5njVZMxGrlW+toglpTtJsaIK7Q=; b=HAWXw5Yo/pigXBMT2SaTaQcH7aNobn3U4jA7phk5xp4cxLkTgVzx0YWzYlsAm0DYv/ DKyglvMtOaPmiKnZkPmSc/ViMbFSvQ8DxXglj1nidcfIjkfaPFX1KJKSE7upM262jkmh wL3uMpsyCGIchn4HnhH2z+hc7Qo7+j1yOBWqdcvpcGLg7xdL9U9TjRi58YtzD6Bxb8qr ifLz+6p75AYdoNUlWMMnI0i1ip8vTmOiZhR1KW4TLePNdStYfgXoMT1MkwO43TWeX5jF TsrXJFvl6As7+mWjRjKuu+P2byT2epJMWSXDO1VUb4zMn9yyol6W0FftsWNjIuxij0h2 jALg== X-Gm-Message-State: AOAM531aYwiakH9eQlSpl5W+KNowhsl6SBYa8wOV2ucHFcN8Z7uUHzbH +hMPricn0bHFhUuGXyYufbIJNg== X-Google-Smtp-Source: ABdhPJwYLFgpfdYepUN2MuHQqFPd1xW8bR0+VIKEYilePW9STlhRYu9TyL1aJNmvMCqqfXnMsSDNrw== X-Received: by 2002:a1c:7409:: with SMTP id p9mr1568025wmc.3.1628115809498; Wed, 04 Aug 2021 15:23:29 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id s14sm3434701wmc.25.2021.08.04.15.23.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Aug 2021 15:23:28 -0700 (PDT) Date: Thu, 5 Aug 2021 00:23:21 +0200 From: Daniel Vetter To: Imre Deak Cc: linux-fbdev@vger.kernel.org, Kai-Heng Feng , dri-devel@lists.freedesktop.org, Thomas Zimmermann , Alex Deucher , intel-gfx@lists.freedesktop.org Subject: Re: [Intel-gfx] [PATCH] fbdev/efifb: Release PCI device's runtime PM ref during FB destroy Message-ID: References: <20210802133551.1904964-1-imre.deak@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210802133551.1904964-1-imre.deak@intel.com> X-Operating-System: Linux phenom 5.10.0-7-amd64 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org On Mon, Aug 02, 2021 at 04:35:51PM +0300, Imre Deak wrote: > Atm the EFI FB driver gets a runtime PM reference for the associated GFX > PCI device during driver probing and releases it only when removing the > driver. > > When fbcon switches to the FB provided by the PCI device's driver (for > instance i915/drmfb), the EFI FB will get only unregistered without the > EFI FB driver getting unloaded, keeping the runtime PM reference > acquired during driver probing. This reference will prevent the PCI > driver from runtime suspending the device. > > Fix this by releasing the RPM reference from the EFI FB's destroy hook, > called when the FB gets unregistered. > > Fixes: a6c0fd3d5a8b ("efifb: Ensure graphics device for efifb stays at PCI D0") > Cc: Kai-Heng Feng > Signed-off-by: Imre Deak Patch looks good: Reviewed-by: Daniel Vetter But I've found a bunch of ordering issues here: - we should probably get the runtime pm reference _before_ we register the framebuffer. There's a race right now about there. - the sysfs_remove_groups and framebuffer_release should also be moved into the destroy callback. This is more a leak type of situation. Cheers, Daniel > --- > drivers/video/fbdev/efifb.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c > index 8ea8f079cde26..25cdea32b9633 100644 > --- a/drivers/video/fbdev/efifb.c > +++ b/drivers/video/fbdev/efifb.c > @@ -47,6 +47,8 @@ static bool use_bgrt = true; > static bool request_mem_succeeded = false; > static u64 mem_flags = EFI_MEMORY_WC | EFI_MEMORY_UC; > > +static struct pci_dev *efifb_pci_dev; /* dev with BAR covering the efifb */ > + > static struct fb_var_screeninfo efifb_defined = { > .activate = FB_ACTIVATE_NOW, > .height = -1, > @@ -243,6 +245,9 @@ static inline void efifb_show_boot_graphics(struct fb_info *info) {} > > static void efifb_destroy(struct fb_info *info) > { > + if (efifb_pci_dev) > + pm_runtime_put(&efifb_pci_dev->dev); > + > if (info->screen_base) { > if (mem_flags & (EFI_MEMORY_UC | EFI_MEMORY_WC)) > iounmap(info->screen_base); > @@ -333,7 +338,6 @@ ATTRIBUTE_GROUPS(efifb); > > static bool pci_dev_disabled; /* FB base matches BAR of a disabled device */ > > -static struct pci_dev *efifb_pci_dev; /* dev with BAR covering the efifb */ > static struct resource *bar_resource; > static u64 bar_offset; > > @@ -603,8 +607,6 @@ static int efifb_remove(struct platform_device *pdev) > unregister_framebuffer(info); > sysfs_remove_groups(&pdev->dev.kobj, efifb_groups); > framebuffer_release(info); > - if (efifb_pci_dev) > - pm_runtime_put(&efifb_pci_dev->dev); > > return 0; > } > -- > 2.27.0 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch