From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:51064 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752390AbeDYKhN (ORCPT ); Wed, 25 Apr 2018 06:37:13 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Merlijn Wajer , Tony Lindgren , Bin Liu Subject: [PATCH 4.14 013/183] usb: musb: call pm_runtime_{get,put}_sync before reading vbus registers Date: Wed, 25 Apr 2018 12:33:53 +0200 Message-Id: <20180425103243.147303287@linuxfoundation.org> In-Reply-To: <20180425103242.532713678@linuxfoundation.org> References: <20180425103242.532713678@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Merlijn Wajer commit df6b074dbe248d8c43a82131e8fd429e401841a5 upstream. 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 Acked-by: Tony Lindgren Signed-off-by: Bin Liu Signed-off-by: Greg Kroah-Hartman --- drivers/usb/musb/musb_core.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/usb/musb/musb_core.c +++ b/drivers/usb/musb/musb_core.c @@ -1780,6 +1780,7 @@ musb_vbus_show(struct device *dev, struc int vbus; u8 devctl; + pm_runtime_get_sync(dev); spin_lock_irqsave(&musb->lock, flags); val = musb->a_wait_bcon; vbus = musb_platform_get_vbus_status(musb); @@ -1793,6 +1794,7 @@ musb_vbus_show(struct device *dev, struc vbus = 0; } spin_unlock_irqrestore(&musb->lock, flags); + pm_runtime_put_sync(dev); return sprintf(buf, "Vbus %s, timeout %lu msec\n", vbus ? "on" : "off", val);