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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 32551C433ED for ; Tue, 20 Apr 2021 07:53:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E5DAF6101E for ; Tue, 20 Apr 2021 07:53:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229874AbhDTHyQ (ORCPT ); Tue, 20 Apr 2021 03:54:16 -0400 Received: from foss.arm.com ([217.140.110.172]:58014 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229552AbhDTHyL (ORCPT ); Tue, 20 Apr 2021 03:54:11 -0400 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 6BA771435; Tue, 20 Apr 2021 00:53:39 -0700 (PDT) Received: from bogus (unknown [10.57.52.142]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3F2973F85F; Tue, 20 Apr 2021 00:53:38 -0700 (PDT) Date: Tue, 20 Apr 2021 08:53:32 +0100 From: Sudeep Holla To: Kai-Heng Feng , Alex Deucher , Thomas Zimmermann , Sudeep Holla , Peter Jones Cc: linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] efifb: Fix runtime pm calls for non PCI efifb device Message-ID: <20210420075332.t56dlpppb6bnpjzd@bogus> References: <20210415102224.2764054-1-sudeep.holla@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210415102224.2764054-1-sudeep.holla@arm.com> User-Agent: NeoMutt/20171215 Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org Gentle Ping! There is boot failure because of this issue with linux-next on few arm platforms with non PCIe efifb. Please review and get the fix merged ASAP so the testing on these platforms can continue with linux-next. On Thu, Apr 15, 2021 at 11:22:24AM +0100, Sudeep Holla wrote: > Commit a6c0fd3d5a8b ("efifb: Ensure graphics device for efifb stays at PCI D0") > added runtime pm calls to probe and remove routines to ensure the PCI > device for efifb stays in D0 state. However not ever efifb is based on > PCI device and efifb_pci_dev can be NULL if that is the case. > > In such cases, we will get a boot splat like below due to NULL dereference: > -->8 > Console: switching to colour frame buffer device 240x67 > fb0: EFI VGA frame buffer device > Unable to handle kernel NULL pointer dereference at virtual address 0000000000000270 > Mem abort info: > ESR = 0x96000004 > EC = 0x25: DABT (current EL), IL = 32 bits > SET = 0, FnV = 0 > EA = 0, S1PTW = 0 > Data abort info: > ISV = 0, ISS = 0x00000004 > CM = 0, WnR = 0 > [0000000000000270] user address but active_mm is swapper > Internal error: Oops: 96000004 [#1] PREEMPT SMP > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.12.0-rc7-next-20210413 #1 > Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform > pstate: 60000005 (nZCv daif -PAN -UAO -TCO BTYPE=--) > pc : pm_runtime_drop_link+0x12c/0x338 > lr : efifb_probe+0x7bc/0x7f0 > Call trace: > pm_runtime_drop_link+0x12c/0x338 > efifb_probe+0x7bc/0x7f0 > platform_probe+0x68/0xd8 > really_probe+0xe4/0x3a8 > driver_probe_device+0x64/0xc8 > device_driver_attach+0x74/0x80 > __driver_attach+0x64/0xf0 > bus_for_each_dev+0x70/0xc0 > driver_attach+0x24/0x30 > bus_add_driver+0x150/0x1f8 > driver_register+0x64/0x120 > __platform_driver_register+0x28/0x38 > efifb_driver_init+0x1c/0x28 > do_one_initcall+0x48/0x2b0 > kernel_init_freeable+0x1e8/0x258 > kernel_init+0x14/0x118 > ret_from_fork+0x10/0x30 > Code: 88027c01 35ffffa2 17fff706 f9800051 (885f7c40) > ---[ end trace 17d8da630bf8ff77 ]--- > Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b > -->8 > > Fix the issue by checking for non-NULL efifb_pci_dev before dereferencing > for runtime pm calls in probe and remove routines. > > Fixes: a6c0fd3d5a8b ("efifb: Ensure graphics device for efifb stays at PCI D0") > Cc: Kai-Heng Feng > Cc: Alex Deucher > Cc: Thomas Zimmermann > Cc: Peter Jones > Signed-off-by: Sudeep Holla > --- > drivers/video/fbdev/efifb.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/video/fbdev/efifb.c b/drivers/video/fbdev/efifb.c > index f58a545b3bf3..8ea8f079cde2 100644 > --- a/drivers/video/fbdev/efifb.c > +++ b/drivers/video/fbdev/efifb.c > @@ -575,7 +575,8 @@ static int efifb_probe(struct platform_device *dev) > goto err_fb_dealoc; > } > fb_info(info, "%s frame buffer device\n", info->fix.id); > - pm_runtime_get_sync(&efifb_pci_dev->dev); > + if (efifb_pci_dev) > + pm_runtime_get_sync(&efifb_pci_dev->dev); > return 0; > > err_fb_dealoc: > @@ -602,7 +603,8 @@ static int efifb_remove(struct platform_device *pdev) > unregister_framebuffer(info); > sysfs_remove_groups(&pdev->dev.kobj, efifb_groups); > framebuffer_release(info); > - pm_runtime_put(&efifb_pci_dev->dev); > + if (efifb_pci_dev) > + pm_runtime_put(&efifb_pci_dev->dev); > > return 0; > } > -- > 2.25.1 > -- Regards, Sudeep