Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753487AbdGXJut (ORCPT ); Mon, 24 Jul 2017 05:50:49 -0400 Received: from mail-lf0-f67.google.com ([209.85.215.67]:36705 "EHLO mail-lf0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752669AbdGXJud (ORCPT ); Mon, 24 Jul 2017 05:50:33 -0400 From: Johan Hovold To: Bin Liu Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Johan Hovold , stable , Alan Stern , Daniel Mack , Dave Gerlach , "Rafael J . Wysocki" , Sebastian Andrzej Siewior , Tony Lindgren Subject: [PATCH] USB: musb: fix external abort on suspend Date: Mon, 24 Jul 2017 11:49:39 +0200 Message-Id: <20170724094939.21477-1-johan@kernel.org> X-Mailer: git-send-email 2.13.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3697 Lines: 97 Make sure that the controller is runtime resumed when system suspending to avoid an external abort when accessing the interrupt registers: Unhandled fault: external abort on non-linefetch (0x1008) at 0xd025840a ... [] (musb_default_readb) from [] (musb_disable_interrupts+0x84/0xa8) [] (musb_disable_interrupts) from [] (musb_suspend+0x38/0xb8) [] (musb_suspend) from [] (platform_pm_suspend+0x3c/0x64) This is easily reproduced on a BBB by enabling the peripheral port only (as the host port may enable the shared clock) and keeping it disconnected so that the controller is runtime suspended. (Well, you would also need to the not-yet-merged am33xx-suspend patches by Dave Gerlach to be able to suspend the BBB.) This is a regression that was introduced by commit 1c4d0b4e1806 ("usb: musb: Remove pm_runtime_set_irq_safe") which allowed the parent glue device to runtime suspend and thereby exposed a couple of older issues: Register accesses without explicitly making sure the controller is runtime resumed during suspend was first introduced by commit c338412b5ded ("usb: musb: unconditionally save and restore the context on suspend") in 3.14. Commit a1fc1920aaaa ("usb: musb: core: make sure musb is in RPM_ACTIVE on resume") later started setting the RPM status to active during resume without first making sure that the parent was runtime resumed. This was also implicitly relying on the parent always being active. Since commit 71723f95463d ("PM / runtime: print error when activating a child to unactive parent") this now also results in following warning: musb-hdrc musb-hdrc.0: runtime PM trying to activate child device musb-hdrc.0 but parent (47401400.usb) is not active This patch has been verified on 4.13-rc2, 4.12 and 4.9 using a BBB (the dsps glue would always be active also in 4.8). Fixes: c338412b5ded ("usb: musb: unconditionally save and restore the context on suspend") Fixes: a1fc1920aaaa ("usb: musb: core: make sure musb is in RPM_ACTIVE on resume") Fixes: 1c4d0b4e1806 ("usb: musb: Remove pm_runtime_set_irq_safe") Cc: stable # 4.8 Cc: Alan Stern Cc: Daniel Mack Cc: Dave Gerlach Cc: Rafael J. Wysocki Cc: Sebastian Andrzej Siewior Cc: Tony Lindgren Signed-off-by: Johan Hovold --- drivers/usb/musb/musb_core.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c index 87cbd56cc761..b67692857daf 100644 --- a/drivers/usb/musb/musb_core.c +++ b/drivers/usb/musb/musb_core.c @@ -2671,6 +2671,13 @@ static int musb_suspend(struct device *dev) { struct musb *musb = dev_to_musb(dev); unsigned long flags; + int ret; + + ret = pm_runtime_get_sync(dev); + if (ret < 0) { + pm_runtime_put_noidle(dev); + return ret; + } musb_platform_disable(musb); musb_disable_interrupts(musb); @@ -2721,14 +2728,6 @@ static int musb_resume(struct device *dev) if ((devctl & mask) != (musb->context.devctl & mask)) musb->port1_status = 0; - /* - * The USB HUB code expects the device to be in RPM_ACTIVE once it came - * out of suspend - */ - pm_runtime_disable(dev); - pm_runtime_set_active(dev); - pm_runtime_enable(dev); - musb_start(musb); spin_lock_irqsave(&musb->lock, flags); @@ -2738,6 +2737,9 @@ static int musb_resume(struct device *dev) error); spin_unlock_irqrestore(&musb->lock, flags); + pm_runtime_mark_last_busy(dev); + pm_runtime_put_autosuspend(dev); + return 0; } -- 2.13.3