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_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 34771C4724C for ; Fri, 1 May 2020 00:56:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 02662206C0 for ; Fri, 1 May 2020 00:56:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="BirI9o13" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727968AbgEAA4M (ORCPT ); Thu, 30 Apr 2020 20:56:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46296 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726384AbgEAA4L (ORCPT ); Thu, 30 Apr 2020 20:56:11 -0400 Received: from mail-pj1-x1044.google.com (mail-pj1-x1044.google.com [IPv6:2607:f8b0:4864:20::1044]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91FFBC035494 for ; Thu, 30 Apr 2020 17:56:11 -0700 (PDT) Received: by mail-pj1-x1044.google.com with SMTP id a5so1698874pjh.2 for ; Thu, 30 Apr 2020 17:56:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=37JzE6dO7W63uNk97bdpwnKTw03BVNHUQMku3iX92TE=; b=BirI9o13LaYlRDUQQps/Dm4/3J8cQB3/DWHqJ6staa7enYULUwkOjG6eGuPtfYsmzK T1tBwiM2AXjVsNj9oV7GxwnT/lBhAvGz664C99GR7nFS54EQfVjJs0ZmK3dHgLD0GEy8 fgZ2tNyglhz05NBmCXBRhyOJAZP/HmC+esSPE= 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=37JzE6dO7W63uNk97bdpwnKTw03BVNHUQMku3iX92TE=; b=m3UjOxHkxgMVvaHmyA1hhqqruvzXSVFbMPlM8rP2khxGFVcsri9O9uHBx1SGEdutC5 sj3vZPeA9EWvS9MxAsJUfKYDKUpZSiZz8JxV5bmz0jQw86CBqsF7KANrU0Cd5F0yTTj4 4SLPytdNBO/p3iNqtEcnEP2lpqXf/jmYsFYQ8jF7+j3sZlGpOxYWoTOb2u+V9SpCvuSu Bg5/HNAQBonf4JJN/H63ZUzMXfIFc5/dlOlBRIj5P8E9GdiZ8Y/Pvkc2dt7aT8bpO4qP vIx5F6uztBma9liOHFg07YD3pzmV9yU1vS/tAofT3Zb92H/QCZ2BVce1UIJUF0lmfCgo cBBQ== X-Gm-Message-State: AGi0PuYTZFgaxL8VkiB4gA3ugwg8ATgYun4wHfGyXtF4tKIA6RLCC69K Jey68Tu5y61o1BhGeEIIQgC9SQ== X-Google-Smtp-Source: APiQypL2EjMoePzDlS7L05+cQm5XN7B9LvgzzFOvwppc9pwXj6C1pVPWOfwR9P4JNsn2pSr2MIgHXg== X-Received: by 2002:a17:902:7592:: with SMTP id j18mr1878591pll.43.1588294570951; Thu, 30 Apr 2020 17:56:10 -0700 (PDT) Received: from google.com ([2620:15c:202:201:476b:691:abc3:38db]) by smtp.gmail.com with ESMTPSA id i18sm752183pjx.33.2020.04.30.17.56.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 30 Apr 2020 17:56:10 -0700 (PDT) Date: Thu, 30 Apr 2020 17:56:09 -0700 From: Prashant Malani To: Daniil Lunev Cc: Enric Balletbo i Serra , LKML , Benson Leung , Guenter Roeck Subject: Re: [PATCH] platform/chrome: cros_ec_typec: Handle NULL EC pointer during probe. Message-ID: <20200501005609.GA131713@google.com> References: <20200428110253.1.I926f6741079cafb04ecb592130aef75b24ad31ae@changeid> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Daniil, On Fri, May 01, 2020 at 10:15:18AM +1000, Daniil Lunev wrote: > On the official revision of coreboot for hatch it doesn't even try to > load Type C. However it gives some warning messages from > cros-usbpd-notify-acpi about EC, So I wonder why the check of the same > type is not appropriate in the typec driver? I think the difference is that GOOG0003 is already present on shipped / official versions of coreboot (so not having that check can cause existing release images/devices to crash), whereas for GOOG0014 that is / isn't the case. Is GOOG0014 present on the official release coreboot image for this device? If so, what's its path (/sys/bus/acpi/devices//path) ? Best regards, -Prashant > > ../chrome/cros_usbpd_notify.c > > /* Get the EC device pointer needed to talk to the EC. */ > ec_dev = dev_get_drvdata(dev->parent); > if (!ec_dev) { > /* > * We continue even for older devices which don't have the > * correct device heirarchy, namely, GOOG0003 is a child > * of GOOG0004. > */ > dev_warn(dev, "Couldn't get Chrome EC device pointer.\n"); > } > > > # dmesg > ... > [ 8.513351] cros-ec-spi spi-PRP0001:02: EC failed to respond in time > [ 8.722072] cros-ec-spi spi-PRP0001:02: EC failed to respond in time > [ 8.729271] cros-ec-spi spi-PRP0001:02: Cannot identify the EC: error -110 > [ 8.736966] cros-ec-spi spi-PRP0001:02: cannot register EC, > fallback to spidev > [ 8.767017] cros_ec_lpcs GOOG0004:00: Chrome EC device registered > [ 8.807537] cros-usbpd-notify-acpi GOOG0003:00: Couldn't get Chrome > EC device pointer. > ... > > On Fri, May 1, 2020 at 2:17 AM Prashant Malani wrote: > > > > Hi Enric, > > > > On Thu, Apr 30, 2020 at 8:26 AM Enric Balletbo i Serra > > wrote: > > > > > > Hi Prashant, > > > > > > On 30/4/20 2:43, Prashant Malani wrote: > > > > On Wed, Apr 29, 2020 at 5:38 PM Daniil Lunev wrote: > > > >> > > > >> [to make it appear on the mailing list as I didn't realize I was in > > > >> hypertext sending mode] > > > >> > > > >> On Thu, Apr 30, 2020 at 10:11 AM Daniil Lunev wrote: > > > >>> > > > >>> Hi Enric. > > > >>> I encountered the issue on a Hatch device when trying running 5.4 kernel on that. After talking to Prashant it seems that any device with coreboot built before a certain point (a particular fix for device hierarchy in ACPI tables of Chrome devices which happened in mid-April) will not be able to correctly initialize the driver and will get a kernel panic trying to do so. > > > > > > > > A clarifying detail here: This should not be seen in any current > > > > *production* device. No prod device firmware will carry the erroneous > > > > ACPI device entry. > > > > > > > > > > Thanks for the clarification. Then, I don't think we need to upstream this. This > > > kind of "defensive-programming" it's not something that should matter to upstream. > > > > Actually, on second thought, I am not 100% sure about this: > > Daniil, is the erroneous ACPI device on a *production* firmware for > > this device (I'm not sure about the vintage of that device's BIOS)? > > > > My apologies for the confusion, Enric and Daniil; but would be good to > > get clarification from Daniil. > > > > Best regards, > > > > > > Thanks, > > > Enric > > > > > > > > > >>> Thanks, > > > >>> Daniil > > > >>> > > > >>> On Thu, Apr 30, 2020 at 7:58 AM Enric Balletbo i Serra wrote: > > > >>>> > > > >>>> Hi Daniil, > > > >>>> > > > >>>> Thank you for the patch. > > > >>>> > > > >>>> On 28/4/20 3:02, Daniil Lunev wrote: > > > >>>>> Missing EC in device hierarchy causes NULL pointer to be returned to the > > > >>>>> probe function which leads to NULL pointer dereference when trying to > > > >>>>> send a command to the EC. This can be the case if the device is missing > > > >>>>> or incorrectly configured in the firmware blob. Even if the situation > > > >>>> > > > >>>> There is any production device with a buggy firmware outside? Or this is just > > > >>>> for defensive programming while developing the firmware? Which device is > > > >>>> affected for this issue? > > > >>>> > > > >>>> Thanks, > > > >>>> Enric > > > >>>> > > > >>>>> occures, the driver shall not cause a kernel panic as the condition is > > > >>>>> not critical for the system functions. > > > >>>>> > > > >>>>> Signed-off-by: Daniil Lunev > > > >>>>> --- > > > >>>>> > > > >>>>> drivers/platform/chrome/cros_ec_typec.c | 5 +++++ > > > >>>>> 1 file changed, 5 insertions(+) > > > >>>>> > > > >>>>> diff --git a/drivers/platform/chrome/cros_ec_typec.c b/drivers/platform/chrome/cros_ec_typec.c > > > >>>>> index 874269c07073..30d99c930445 100644 > > > >>>>> --- a/drivers/platform/chrome/cros_ec_typec.c > > > >>>>> +++ b/drivers/platform/chrome/cros_ec_typec.c > > > >>>>> @@ -301,6 +301,11 @@ static int cros_typec_probe(struct platform_device *pdev) > > > >>>>> > > > >>>>> typec->dev = dev; > > > >>>>> typec->ec = dev_get_drvdata(pdev->dev.parent); > > > >>>>> + if (!typec->ec) { > > > >>>>> + dev_err(dev, "Failed to get Cros EC data\n"); > > > >>>>> + return -EINVAL; > > > >>>>> + } > > > >>>>> + > > > >>>>> platform_set_drvdata(pdev, typec); > > > >>>>> > > > >>>>> ret = cros_typec_get_cmd_version(typec); > > > >>>>>