[PATCH 4.9 53/66] usb: musb: Fix host mode error -71 regression

From: Greg Kroah-Hartman
Date: Tue Feb 07 2017 - 08:08:42 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Tony Lindgren <tony@xxxxxxxxxxx>

commit 407788b51db6f6aab499d02420082f436abf3238 upstream.

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>
Signed-off-by: Bin Liu <b-liu@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/musb/musb_core.c | 15 ++-------------
drivers/usb/musb/musb_core.h | 1 -
2 files changed, 2 insertions(+), 14 deletions(-)

--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -578,11 +578,11 @@ static irqreturn_t musb_stage0_irq(struc
| 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;
@@ -2691,11 +2691,6 @@ static int musb_resume(struct device *de
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
@@ -2747,12 +2742,6 @@ static int musb_runtime_resume(struct de

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)
--- 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;