From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3386012-1519549325-2-2127686000154160219 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.001, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='com', MailFrom='org' X-Spam-charsets: plain='utf-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-usb-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1519549325; b=TpBLtPuyczxBZz6v/ml7ZC+WWu9+N0GQDMEzwhRqS/IY8bq FAlUw7RLwtLAQc0rSyCXjdDXEIW3Fiji4UA7P+2OXeyZ2EHhXqvliV9iEi4/fnKh Js0NI3oAFCjo9w7ao1J0ALOv2jLZ1Psc3AJcin//eob1JqyLLYZsJSNGh2kOYkZC aA1HdC9QWo5UAkq2n+03qzxgyaH8q4vjxBfcI6B+yKKsHj4fQKUD4EadTt+axlqo OKHuwmel/vTiyKs0GY4FPkso/hAQBdpBXiouZulaJN+O0VdSE355umPMnohJuFsY bPFN2Ix6Fejwm2lSYG3a3ZTJw/oJ5XoeveSmfJQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=subject:to:cc:references:from:message-id :date:mime-version:in-reply-to:content-type :content-transfer-encoding:sender:list-id; s=arctest; t= 1519549325; bh=iHfHZI30eanuN2Z9X3LcCJ86qDQ8Rm3eyetO6IpgN1g=; b=c 5t1ITGNRdXP3jOzPKN9wIQCM+Bwzuc0IMl8ywdqXqxX065Hy35PWgSz+jxRUkeEX yZx5f/em0cuzt9gmfUirdwjG90Uj0PYN6it1oocfvVaAsXADHO/vB2UPLyOal2kb bBE+Z42G7xf08mYy0AM19zEY31HD5IsCI6LD4/lbMA07wSshCQ4KjzQAOp3whcQQ ClpoQWkucIhfjC4u+x5QR34qVqpj7ACyH80seUUhbp3g4PYtGu4XBzPQIBD9cw5r kbojGEQ4aaNetGq8PLiSmJq1/uXvXJqkxk9NxBhF4bGXTXyHDv5Aji7yk87ggpuw 0AbW/hIfnr3M3mKV8V0uQ== ARC-Authentication-Results: i=1; mx4.messagingengine.com; arc=none (no signatures found); dkim=fail (body has been altered; 2048-bit rsa key sha256) header.d=cogentembedded-com.20150623.gappssmtp.com header.i=@cogentembedded-com.20150623.gappssmtp.com header.b=lQasykER x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=20150623; dmarc=none (p=none,has-list-id=yes,d=none) header.from=cogentembedded.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-usb-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-google-dkim=fail (body has been altered; 2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=EXRRNWR0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=cogentembedded.com header.result=pass header_is_org_domain=yes Authentication-Results: mx4.messagingengine.com; arc=none (no signatures found); dkim=fail (body has been altered; 2048-bit rsa key sha256) header.d=cogentembedded-com.20150623.gappssmtp.com header.i=@cogentembedded-com.20150623.gappssmtp.com header.b=lQasykER x-bits=2048 x-keytype=rsa x-algorithm=sha256 x-selector=20150623; dmarc=none (p=none,has-list-id=yes,d=none) header.from=cogentembedded.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-usb-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-google-dkim=fail (body has been altered; 2048-bit rsa key) header.d=1e100.net header.i=@1e100.net header.b=EXRRNWR0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=cogentembedded.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751540AbeBYJBt (ORCPT ); Sun, 25 Feb 2018 04:01:49 -0500 Received: from mail-lf0-f46.google.com ([209.85.215.46]:44226 "EHLO mail-lf0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751018AbeBYJBs (ORCPT ); Sun, 25 Feb 2018 04:01:48 -0500 X-Google-Smtp-Source: AG47ELuNS3t3vXWR5AbJCuVyb0Xw/4YX2le4IN/4h3tWY35iJsoRM39Kj+bWeXooaZSd4spcdCmaEA== Subject: Re: [RFC PATCH] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers To: Merlijn Wajer , linux-omap@vger.kernel.org Cc: tony@atomide.com, Bin Liu , Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org References: <20180224205151.12079-1-merlijn@wizzup.org> From: Sergei Shtylyov Message-ID: Date: Sun, 25 Feb 2018 12:01:46 +0300 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180224205151.12079-1-merlijn@wizzup.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-usb-owner@vger.kernel.org X-Mailing-List: linux-usb@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Hello! On 2/24/2018 11:51 PM, Merlijn Wajer wrote: > Without pm_runtime_{get,put}_sync calls in place, reading > vbus status via /sys causes the following error: > > Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa0ab060 > pgd = b333e822 > [fa0ab060] *pgd=48011452(bad) > > [] (musb_default_readb) from [] (musb_vbus_show+0x58/0xe4) > [] (musb_vbus_show) from [] (dev_attr_show+0x20/0x44) > [] (dev_attr_show) from [] (sysfs_kf_seq_show+0x80/0xdc) > [] (sysfs_kf_seq_show) from [] (seq_read+0x250/0x448) > [] (seq_read) from [] (__vfs_read+0x1c/0x118) > [] (__vfs_read) from [] (vfs_read+0x90/0x144) > [] (vfs_read) from [] (SyS_read+0x3c/0x74) > [] (SyS_read) from [] (ret_fast_syscall+0x0/0x54) > > Solution was suggested by Tony Lindgren . > > Signed-off-by: Merlijn Wajer > --- > drivers/usb/musb/musb_core.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c > index ea5013aa69e2..182611f76af3 100644 > --- a/drivers/usb/musb/musb_core.c > +++ b/drivers/usb/musb/musb_core.c [...] > @@ -1767,6 +1769,9 @@ musb_vbus_show(struct device *dev, struct device_attribute *attr, char *buf) > vbus = 1; > else > vbus = 0; > + > + pm_runtime_put_sync(dev); > + Empty line not needed here. > } > spin_unlock_irqrestore(&musb->lock, flags); > MBR, Sergei