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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 31DFCC04EBD for ; Tue, 16 Oct 2018 09:47:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE85320881 for ; Tue, 16 Oct 2018 09:47:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CE85320881 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727043AbeJPRgq (ORCPT ); Tue, 16 Oct 2018 13:36:46 -0400 Received: from mail-wm1-f67.google.com ([209.85.128.67]:33794 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726581AbeJPRgp (ORCPT ); Tue, 16 Oct 2018 13:36:45 -0400 Received: by mail-wm1-f67.google.com with SMTP id z25-v6so24908308wmf.1 for ; Tue, 16 Oct 2018 02:47:08 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=qiaavaWBwbzt5PAbqq2mbzkmAV/UfBJmAUnBT7JtiYg=; b=ohPbcxnoBnFwxAYYsMKIb1dWuNZSkSGDE1UMN/j4e1LMwrwpfmo6mQByE+kkyVg/AL r4uUtCwUE8aTIY0wRPog/g8Cpl+DSQFFrwD5q550aJJQBKZ1K+VvWzi3jLDuXJTs+I4j uz7RlUtmWQmHTSiw6N6axU9ycuNAdF1ccc8+CD3QKhv22dieaKkKTVKQ+PZOdpO1mCYj yxmPoFFjDbhdIquAhpD3q0PbhGC5wCOl8p1iDP444iRA46WcYf3ZYc9+Gt6A6oZQ1U+U gyOLJvd9zS6KgYC//56RpR01Ghtww2LJgEuqo424hh3kA4Oz0FWdEtVgEv3pKlANuHo2 uACQ== X-Gm-Message-State: ABuFfojUj41OHEnbl4/vcoHLn2qnVay3LGworApSRpNxbeTMhx3mpj2j DTZOY30PvaZ7dg/2Lt9Er7pzHQ== X-Google-Smtp-Source: ACcGV61cMGNrg38kJUyHe44fvCkE0ZiNAEZSeu5d46mZDgjYErYcu5QpMTt+QDnPYJLrwGOc4eXOJg== X-Received: by 2002:a1c:4385:: with SMTP id q127-v6mr16226271wma.28.1539683227343; Tue, 16 Oct 2018 02:47:07 -0700 (PDT) Received: from [192.168.1.13] ([90.168.169.92]) by smtp.gmail.com with ESMTPSA id b71-v6sm14256343wma.13.2018.10.16.02.47.06 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 16 Oct 2018 02:47:06 -0700 (PDT) Subject: Re: [PATCH 2/3] driver core: add deferring probe reason to devices_deferred property To: Andrzej Hajda , Greg Kroah-Hartman Cc: Bartlomiej Zolnierkiewicz , Marek Szyprowski , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, andy.shevchenko@gmail.com, Mark Brown References: <20181016072244.1216-1-a.hajda@samsung.com> <20181016072244.1216-3-a.hajda@samsung.com> From: Javier Martinez Canillas Message-ID: Date: Tue, 16 Oct 2018 11:47:05 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <20181016072244.1216-3-a.hajda@samsung.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/16/2018 09:22 AM, Andrzej Hajda wrote: > /sys/kernel/debug/devices_deferred property contains list of deferred devices. > This list does not contain reason why the driver deferred probe, the patch > improves it. > The natural place to set the reason is probe_err function introduced recently, > ie. if probe_err will be called with -EPROBE_DEFER instead of printk the message > will be attached to deferred device and printed when user read devices_deferred > property. > > Signed-off-by: Andrzej Hajda > --- > drivers/base/base.h | 3 +++ > drivers/base/core.c | 15 +++++++++------ > drivers/base/dd.c | 34 +++++++++++++++++++++++++++++++++- > 3 files changed, 45 insertions(+), 7 deletions(-) > > diff --git a/drivers/base/base.h b/drivers/base/base.h > index 7a419a7a6235..6f9371bfe40b 100644 > --- a/drivers/base/base.h > +++ b/drivers/base/base.h > @@ -75,6 +75,7 @@ struct device_private { > struct klist_node knode_driver; > struct klist_node knode_bus; > struct list_head deferred_probe; > + char *deferred_probe_msg; > struct device *device; > }; > #define to_device_private_parent(obj) \ > @@ -113,6 +114,8 @@ extern void device_release_driver_internal(struct device *dev, > extern void driver_detach(struct device_driver *drv); > extern int driver_probe_device(struct device_driver *drv, struct device *dev); > extern void driver_deferred_probe_del(struct device *dev); > +extern void __deferred_probe_set_msg(const struct device *dev, const char *fmt, > + va_list args); > static inline int driver_match_device(struct device_driver *drv, > struct device *dev) > { > diff --git a/drivers/base/core.c b/drivers/base/core.c > index 23fabefb217a..df9895adf11b 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -3076,6 +3076,7 @@ define_dev_printk_level(_dev_info, KERN_INFO); > * > * This helper implements common pattern present in probe functions for error > * checking: print message if the error is not -EPROBE_DEFER and propagate it. > + * In case of -EPROBE_DEFER it sets defer probe reason. > * It replaces code sequence: > * if (err != -EPROBE_DEFER) > * dev_err(dev, ...); > @@ -3091,15 +3092,17 @@ int probe_err(const struct device *dev, int err, const char *fmt, ...) > struct va_format vaf; > va_list args; > > - if (err != -EPROBE_DEFER) { > - va_start(args, fmt); > + va_start(args, fmt); > > - vaf.fmt = fmt; > - vaf.va = &args; > + vaf.fmt = fmt; > + vaf.va = &args; > > + if (err != -EPROBE_DEFER) > __dev_printk(KERN_ERR, dev, &vaf); > - va_end(args); > - } > + else > + __deferred_probe_set_msg(dev, fmt, args); > + > + va_end(args); > > return err; > } > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index 169412ee4ae8..e2f81e538d4b 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -27,6 +27,7 @@ > #include > #include > #include > +#include > > #include "base.h" > #include "power/power.h" > @@ -132,6 +133,8 @@ void driver_deferred_probe_del(struct device *dev) > if (!list_empty(&dev->p->deferred_probe)) { > dev_dbg(dev, "Removed from deferred list\n"); > list_del_init(&dev->p->deferred_probe); > + kfree(dev->p->deferred_probe_msg); > + dev->p->deferred_probe_msg = NULL; > } > mutex_unlock(&deferred_probe_mutex); > } > @@ -202,6 +205,32 @@ void device_unblock_probing(void) > driver_deferred_probe_trigger(); > } > > +/* > + * __deferred_probe_set_msg() - Set defer probe reason message for device > + */ > +void __deferred_probe_set_msg(const struct device *dev, const char *fmt, > + va_list args) > +{ > + const int size = 128; > + char **p; > + int n; > + > + mutex_lock(&deferred_probe_mutex); > + > + p = &dev->p->deferred_probe_msg; > + if (!*p) { > + *p = kmalloc(size, GFP_KERNEL); > + if (!*p) > + goto end; > + } > + n = snprintf(*p, size, "%s %s: ", dev_driver_string(dev), dev_name(dev)); > + if (n < size) > + vsnprintf(*p + n, size - n, fmt, args); I wonder if the vsnprintf() return value should be checked and print a warning if the message was truncated. Probably 128 is enough for most error messages? Reviewed-by: Javier Martinez Canillas Best regards, -- Javier Martinez Canillas Software Engineer - Desktop Hardware Enablement Red Hat