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@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 2 insertions, 14 deletions

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index fca288bbc800..cd40467be3c5 100644
--- 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
index ade902ea1221..ce5a18c98c6d 100644
--- 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;