* Bin Liu <b-liu@xxxxxx> [170118 10:49]:
> On Wed, Jan 18, 2017 at 10:44:32AM -0800, Tony Lindgren wrote:
> > * Tony Lindgren <tony@xxxxxxxxxxx> [170118 10:15]:
> > > * Grygorii Strashko <grygorii.strashko@xxxxxx> [170118 10:05]:
> > > >
> > > >
> > > > On 01/18/2017 10:53 AM, Tony Lindgren wrote:
> > > > > Hi,
> > > > >
> > > > > * Bin Liu <b-liu@xxxxxx> [170118 06:26]:
> > > > >> With this v3, I still get -71 error when a device is plugged to a hub to
> > > > >> musb. It doesn't happen though if the device is already plugged to the hub
> > > > >> before attaching the hub to musb.
> > > > >>
> > > > >> [ 177.579300] usb 1-1: reset high-speed USB device number 2 using musb-hdrc
> > > > >> [ 177.719308] usb 1-1: device descriptor read/64, error -71
> > > > >> [ 178.350297] usb 1-1.1: new high-speed USB device number 4 using musb-hdrc
> > > > >
> > > > > I think the -71 issue is a different regression. I've verified that v4.8.y
> > > > > does not have this, but v4.9.y does have it.
> > > > >
> > > > > So far the easiest way for me to reproduce the -71 problem is by plugging
> > > > > a USB drive into a connected hub. If I connect the hub with USB drive already
> > > > > plugged into the hub, it does not happen.
> > ...
> >
> > > > Sry, but wouldn't be more simple and safe just to drop PM runtime from this driver,
> > > > as it is part of musb and musb PM state expected to be handled properly by PM runtime now.
> > >
> > > Well we still need PM runtime in cppi41 to initialize it when it gets
> > > probed and idle it when not used even if musb modules are not loaded.
> > >
> > > Unfortunately until musb_cppi41.c dma calls are fixed, we can't do
> > > any sane use counting in cppi41.c without adding timeout handling
> > > to it.
> > >
> > > > More over, There is another possibility related to the current PM runtime implementation and autosuspend
> > > > - it might introduce delay between time when musb request desc push and time when cppi will actually
> > > > put this desc in HW queue if cppi was not active.
> > > > For example, there might not be -71 error seen if CPPI autosuspend is disabled
> > > > (cppi is active all the time) before plug-in hub and then USB drive.
> > >
> > > I already checked that. The -71 error seems to be a separate issue.
> >
> > OK found it. I can make v4.8.17 produce -71 errors with just commit
> > 467d5c980709 ("usb: musb: Implement session bit based runtime PM for
> > musb-core") applied on top of it. So looks like we're missing some
> > musb quirk handling for the devctl session bit.
>
> Nice!
And here's a fix for the error -71 regression.
Bin, can you review and test your earlier case mentioned in
commit 9298b4aad37e ("usb: musb: fix device hotplug behind hub") with
the patch below to make sure this is safe to do now starting with v4.9?
Regards,
Tony
8< -----------------------
>From tony Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@xxxxxxxxxxx>
Date: Wed, 18 Jan 2017 12:31:25 -0800
Subject: [PATCH] usb: musb: Fix host mode error -71 regression
Commit 467d5c980709 ("usb: musb: Implement session bit based runtime PM for
musb-core") started implementing musb generic runtime PM support by
introducing devctl register session bit based state control.
This caused a regression where if a USB mass storage device is connected
to a USB hub, we can get:
usb 1-1: reset high-speed USB device number 2 using musb-hdrc
usb 1-1: device descriptor read/64, error -71
usb 1-1.1: new high-speed USB device number 4 using musb-hdrc
This is because before the USB storage device is connected, musb is
in OTG_STATE_A_SUSPEND. And we currently only set need_finish_resume
in musb_stage0_irq() and the related code calling finish_resume_work
in musb_resume() and musb_runtime_resume() never gets called.
To fix the issue, we can call schedule_delayed_work() directly in
musb_stage0_irq() to have finish_resume_work run.
And we should no longer never get interrupts when when suspended.
We have changed musb to no longer need pm_runtime_irqsafe().
The need_finish_resume flag was added in commit 9298b4aad37e ("usb:
musb: fix device hotplug behind hub") and no longer applies as far
as I can tell. So let's just remove the earlier code that no longer
is needed.
Fixes: 467d5c980709 ("usb: musb: Implement session bit based
runtime PM for musb-core")
Reported-by: Bin Liu <b-liu@xxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
drivers/usb/musb/musb_core.c | 15 ++-------------
drivers/usb/musb/musb_core.h | 1 -
2 files changed, 2 insertions(+), 14 deletions(-)
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -594,11 +594,11 @@ static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb,
| MUSB_PORT_STAT_RESUME;
musb->rh_timer = jiffies
+ msecs_to_jiffies(USB_RESUME_TIMEOUT);
- musb->need_finish_resume = 1;
-
musb->xceiv->otg->state = OTG_STATE_A_HOST;
musb->is_active = 1;
musb_host_resume_root_hub(musb);
+ schedule_delayed_work(&musb->finish_resume_work,
+ msecs_to_jiffies(USB_RESUME_TIMEOUT));
break;
case OTG_STATE_B_WAIT_ACON:
musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
@@ -2710,11 +2710,6 @@ static int musb_resume(struct device *dev)
mask = MUSB_DEVCTL_BDEVICE | MUSB_DEVCTL_FSDEV | MUSB_DEVCTL_LSDEV;
if ((devctl & mask) != (musb->context.devctl & mask))
musb->port1_status = 0;
- if (musb->need_finish_resume) {
- musb->need_finish_resume = 0;
- schedule_delayed_work(&musb->finish_resume_work,
- msecs_to_jiffies(USB_RESUME_TIMEOUT));
- }
/*
* The USB HUB code expects the device to be in RPM_ACTIVE once it came
@@ -2766,12 +2761,6 @@ static int musb_runtime_resume(struct device *dev)
musb_restore_context(musb);
- if (musb->need_finish_resume) {
- musb->need_finish_resume = 0;
- schedule_delayed_work(&musb->finish_resume_work,
- msecs_to_jiffies(USB_RESUME_TIMEOUT));
- }
-
spin_lock_irqsave(&musb->lock, flags);
error = musb_run_resume_work(musb);
if (error)
diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -410,7 +410,6 @@ struct musb {
/* is_suspended means USB B_PERIPHERAL suspend */
unsigned is_suspended:1;
- unsigned need_finish_resume :1;
/* may_wakeup means remote wakeup is enabled */
unsigned may_wakeup:1;
--
2.11.0
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