From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bin Liu Subject: Re: [PATCH] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers Date: Mon, 26 Feb 2018 09:57:16 -0600 Message-ID: <20180226155716.GB20609@uda0271908> References: <20180226105609.22514-1-merlijn@wizzup.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <20180226105609.22514-1-merlijn@wizzup.org> Sender: linux-kernel-owner@vger.kernel.org To: Merlijn Wajer Cc: linux-omap@vger.kernel.org, tony@atomide.com, Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-omap@vger.kernel.org Hi, On Mon, Feb 26, 2018 at 11:56:08AM +0100, 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 | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c > index eef4ad578b31..ceaa40ef0e73 100644 > --- a/drivers/usb/musb/musb_core.c > +++ b/drivers/usb/musb/musb_core.c > @@ -1760,6 +1760,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf) > val = musb->a_wait_bcon; > vbus = musb_platform_get_vbus_status(musb); > if (vbus < 0) { > + pm_runtime_get_sync(dev); > + > /* Use default MUSB method by means of DEVCTL register */ > devctl = musb_readb(musb->mregs, MUSB_DEVCTL); > if ((devctl & MUSB_DEVCTL_VBUS) > @@ -1767,6 +1769,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf) > vbus = 1; > else > vbus = 0; > + > + pm_runtime_put_sync(dev); > } > spin_unlock_irqrestore(&musb->lock, flags); Thanks for the patch, but I got spinlock deadlock when testing it. I think the function pair should be at the outside scope of the spin_lock/unlock, doesn't it? Regards, -Bin. From mboxrd@z Thu Jan 1 00:00:00 1970 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Subject: usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers From: Bin Liu Message-Id: <20180226155716.GB20609@uda0271908> Date: Mon, 26 Feb 2018 09:57:16 -0600 To: Merlijn Wajer Cc: linux-omap@vger.kernel.org, tony@atomide.com, Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org List-ID: SGksCgpPbiBNb24sIEZlYiAyNiwgMjAxOCBhdCAxMTo1NjowOEFNICswMTAwLCBNZXJsaWpuIFdh amVyIHdyb3RlOgo+IFdpdGhvdXQgcG1fcnVudGltZV97Z2V0LHB1dH1fc3luYyBjYWxscyBpbiBw bGFjZSwgcmVhZGluZwo+IHZidXMgc3RhdHVzIHZpYSAvc3lzIGNhdXNlcyB0aGUgZm9sbG93aW5n IGVycm9yOgo+IAo+IFVuaGFuZGxlZCBmYXVsdDogZXh0ZXJuYWwgYWJvcnQgb24gbm9uLWxpbmVm ZXRjaCAoMHgxMDI4KSBhdCAweGZhMGFiMDYwCj4gcGdkID0gYjMzM2U4MjIKPiBbZmEwYWIwNjBd ICpwZ2Q9NDgwMTE0NTIoYmFkKQo+IAo+IFs8YzA1MjYxYjA+XSAobXVzYl9kZWZhdWx0X3JlYWRi KSBmcm9tIFs8YzA1MjViZDA+XSAobXVzYl92YnVzX3Nob3crMHg1OC8weGU0KQo+IFs8YzA1MjVi ZDA+XSAobXVzYl92YnVzX3Nob3cpIGZyb20gWzxjMDRjMDE0OD5dIChkZXZfYXR0cl9zaG93KzB4 MjAvMHg0NCkKPiBbPGMwNGMwMTQ4Pl0gKGRldl9hdHRyX3Nob3cpIGZyb20gWzxjMDI1OWY3ND5d IChzeXNmc19rZl9zZXFfc2hvdysweDgwLzB4ZGMpCj4gWzxjMDI1OWY3ND5dIChzeXNmc19rZl9z ZXFfc2hvdykgZnJvbSBbPGMwMjEwYmFjPl0gKHNlcV9yZWFkKzB4MjUwLzB4NDQ4KQo+IFs8YzAy MTBiYWM+XSAoc2VxX3JlYWQpIGZyb20gWzxjMDFlZGI0MD5dIChfX3Zmc19yZWFkKzB4MWMvMHgx MTgpCj4gWzxjMDFlZGI0MD5dIChfX3Zmc19yZWFkKSBmcm9tIFs8YzAxZWRjY2M+XSAodmZzX3Jl YWQrMHg5MC8weDE0NCkKPiBbPGMwMWVkY2NjPl0gKHZmc19yZWFkKSBmcm9tIFs8YzAxZWUxZDA+ XSAoU3lTX3JlYWQrMHgzYy8weDc0KQo+IFs8YzAxZWUxZDA+XSAoU3lTX3JlYWQpIGZyb20gWzxj MDEwNmZlMD5dIChyZXRfZmFzdF9zeXNjYWxsKzB4MC8weDU0KQo+IAo+IFNvbHV0aW9uIHdhcyBz dWdnZXN0ZWQgYnkgVG9ueSBMaW5kZ3JlbiA8dG9ueUBhdG9taWRlLmNvbT4uCj4gCj4gU2lnbmVk LW9mZi1ieTogTWVybGlqbiBXYWplciA8bWVybGlqbkB3aXp6dXAub3JnPgo+IC0tLQo+ICBkcml2 ZXJzL3VzYi9tdXNiL211c2JfY29yZS5jIHwgNCArKysrCj4gIDEgZmlsZSBjaGFuZ2VkLCA0IGlu c2VydGlvbnMoKykKPiAKPiBkaWZmIC0tZ2l0IGEvZHJpdmVycy91c2IvbXVzYi9tdXNiX2NvcmUu YyBiL2RyaXZlcnMvdXNiL211c2IvbXVzYl9jb3JlLmMKPiBpbmRleCBlZWY0YWQ1NzhiMzEuLmNl YWE0MGVmMGU3MyAxMDA2NDQKPiAtLS0gYS9kcml2ZXJzL3VzYi9tdXNiL211c2JfY29yZS5jCj4g KysrIGIvZHJpdmVycy91c2IvbXVzYi9tdXNiX2NvcmUuYwo+IEBAIC0xNzYwLDYgKzE3NjAsOCBA QCB2YnVzX3Nob3coc3RydWN0IGRldmljZSAqZGV2LCBzdHJ1Y3QgZGV2aWNlX2F0dHJpYnV0ZSAq YXR0ciwgY2hhciAqYnVmKQo+ICAJdmFsID0gbXVzYi0+YV93YWl0X2Jjb247Cj4gIAl2YnVzID0g bXVzYl9wbGF0Zm9ybV9nZXRfdmJ1c19zdGF0dXMobXVzYik7Cj4gIAlpZiAodmJ1cyA8IDApIHsK PiArCQlwbV9ydW50aW1lX2dldF9zeW5jKGRldik7Cj4gKwo+ICAJCS8qIFVzZSBkZWZhdWx0IE1V U0IgbWV0aG9kIGJ5IG1lYW5zIG9mIERFVkNUTCByZWdpc3RlciAqLwo+ICAJCWRldmN0bCA9IG11 c2JfcmVhZGIobXVzYi0+bXJlZ3MsIE1VU0JfREVWQ1RMKTsKPiAgCQlpZiAoKGRldmN0bCAmIE1V U0JfREVWQ1RMX1ZCVVMpCj4gQEAgLTE3NjcsNiArMTc2OSw4IEBAIHZidXNfc2hvdyhzdHJ1Y3Qg ZGV2aWNlICpkZXYsIHN0cnVjdCBkZXZpY2VfYXR0cmlidXRlICphdHRyLCBjaGFyICpidWYpCj4g IAkJCXZidXMgPSAxOwo+ICAJCWVsc2UKPiAgCQkJdmJ1cyA9IDA7Cj4gKwo+ICsJCXBtX3J1bnRp bWVfcHV0X3N5bmMoZGV2KTsKPiAgCX0KPiAgCXNwaW5fdW5sb2NrX2lycXJlc3RvcmUoJm11c2It PmxvY2ssIGZsYWdzKTsKClRoYW5rcyBmb3IgdGhlIHBhdGNoLCBidXQgSSBnb3Qgc3BpbmxvY2sg ZGVhZGxvY2sgd2hlbiB0ZXN0aW5nIGl0LiBJCnRoaW5rIHRoZSBmdW5jdGlvbiBwYWlyIHNob3Vs ZCBiZSBhdCB0aGUgb3V0c2lkZSBzY29wZSBvZiB0aGUKc3Bpbl9sb2NrL3VubG9jaywgZG9lc24n dCBpdD8KClJlZ2FyZHMsCi1CaW4uCi0tLQpUbyB1bnN1YnNjcmliZSBmcm9tIHRoaXMgbGlzdDog c2VuZCB0aGUgbGluZSAidW5zdWJzY3JpYmUgbGludXgtdXNiIiBpbgp0aGUgYm9keSBvZiBhIG1l c3NhZ2UgdG8gbWFqb3Jkb21vQHZnZXIua2VybmVsLm9yZwpNb3JlIG1ham9yZG9tbyBpbmZvIGF0 ICBodHRwOi8vdmdlci5rZXJuZWwub3JnL21ham9yZG9tby1pbmZvLmh0bWwK From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3237508-1519660655-2-14474676653164714730 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no ("Email failed DMARC policy for domain") 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='us-ascii' X-IgnoreVacation: yes ("Email failed DMARC policy for domain") 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; 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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-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=ti.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752217AbeBZP5X (ORCPT ); Mon, 26 Feb 2018 10:57:23 -0500 Received: from lelnx194.ext.ti.com ([198.47.27.80]:48383 "EHLO lelnx194.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751947AbeBZP5V (ORCPT ); Mon, 26 Feb 2018 10:57:21 -0500 Date: Mon, 26 Feb 2018 09:57:16 -0600 From: Bin Liu To: Merlijn Wajer CC: , , Greg Kroah-Hartman , , Subject: Re: [PATCH] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers Message-ID: <20180226155716.GB20609@uda0271908> Mail-Followup-To: Bin Liu , Merlijn Wajer , linux-omap@vger.kernel.org, tony@atomide.com, Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org References: <20180226105609.22514-1-merlijn@wizzup.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20180226105609.22514-1-merlijn@wizzup.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 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: Hi, On Mon, Feb 26, 2018 at 11:56:08AM +0100, 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 | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c > index eef4ad578b31..ceaa40ef0e73 100644 > --- a/drivers/usb/musb/musb_core.c > +++ b/drivers/usb/musb/musb_core.c > @@ -1760,6 +1760,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf) > val = musb->a_wait_bcon; > vbus = musb_platform_get_vbus_status(musb); > if (vbus < 0) { > + pm_runtime_get_sync(dev); > + > /* Use default MUSB method by means of DEVCTL register */ > devctl = musb_readb(musb->mregs, MUSB_DEVCTL); > if ((devctl & MUSB_DEVCTL_VBUS) > @@ -1767,6 +1769,8 @@ vbus_show(struct device *dev, struct device_attribute *attr, char *buf) > vbus = 1; > else > vbus = 0; > + > + pm_runtime_put_sync(dev); > } > spin_unlock_irqrestore(&musb->lock, flags); Thanks for the patch, but I got spinlock deadlock when testing it. I think the function pair should be at the outside scope of the spin_lock/unlock, doesn't it? Regards, -Bin.