This is a note to let you know that I've just added the patch titled
usb: musb: core: make sure musb is in RPM_ACTIVE on resume
to my usb git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git
in the usb-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
>From a1fc1920aaaaeadc7cf9d80fc16e6b8eca722b44 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Date: Thu, 13 Nov 2014 18:33:08 +0100
Subject: usb: musb: core: make sure musb is in RPM_ACTIVE on resume
On am335x-evm with musb in host mode and using it as a wakeup source the
following happens once the CPU comes out of suspend to ram:
|PM: Wakeup source MPU_WAKE
|PM: noirq resume of devices complete after 15.453 msecs
|PM: early resume of devices complete after 2.222 msecs
|PM: resume of devices complete after 507.351 msecs
|Restarting tasks ...
|------------[ cut here ]------------
|WARNING: CPU: 0 PID: 322 at drivers/usb/core/urb.c:339 usb_submit_urb+0x494/0x4c8()
|URB cc0db380 submitted while active
|[<c0348e64>] (usb_submit_urb) from [<c0340f94>] (hub_activate+0x2b8/0x49c)
|[<c0340f94>] (hub_activate) from [<c03411dc>] (hub_resume+0x14/0x1c)
|[<c03411dc>] (hub_resume) from [<c034be10>] (usb_resume_interface.isra.4+0xdc/0x110)
|[<c034be10>] (usb_resume_interface.isra.4) from [<c034beb0>] (usb_resume_both+0x6c/0x13c)
|[<c034beb0>] (usb_resume_both) from [<c034cca4>] (usb_runtime_resume+0x10/0x14)
|[<c034cca4>] (usb_runtime_resume) from [<c02bbd80>] (__rpm_callback+0x2c/0x60)
|[<c02bbd80>] (__rpm_callback) from [<c02bbdd4>] (rpm_callback+0x20/0x74)
|[<c02bbdd4>] (rpm_callback) from [<c02bcc48>] (rpm_resume+0x380/0x548)
|[<c02bcc48>] (rpm_resume) from [<c02bcb00>] (rpm_resume+0x238/0x548)
|[<c02bcb00>] (rpm_resume) from [<c02bd08c>] (__pm_runtime_resume+0x64/0x94)
|[<c02bd08c>] (__pm_runtime_resume) from [<c034b5a4>] (usb_autopm_get_interface+0x18/0x5c)
|[<c034b5a4>] (usb_autopm_get_interface) from [<c03438b8>] (hub_thread+0x10c/0x115c)
|[<c03438b8>] (hub_thread) from [<c005a70c>] (kthread+0xbc/0xd8)
|---[ end trace 036aa5fe78203142 ]---
|hub 1-0:1.0: activate --> -16
|hub 2-0:1.0: activate --> -16
The reason for this backtrace is the attempt of the USB code to resume
the HUB twice and thus enqueue the status URB twice.
Alan Stern was a great help by explaining how the USB code supposed to
work and what is most likely the problem. The root problem is that after
resume the musb runtime-suspend state remains RPM_SUSPENDED.
According to git log it RPM was added for the omap2430 platform. If I
understand it correct the omap2430 invokes a get on musb once a cable is
connected and a put once the cable is gone. In between the device could
go auto-idle/off. Not sure what happens when the device goes into suspend
but then I guess it was gadget only.
On DSPS I see only a get in probe and put in remove function. This would
forbid RPM from working but then the devices enterns suspended state
anyway :)
To get rid of this warning, I set the device state to RPM_ACTIVE which
the expected state.
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
---
drivers/usb/musb/musb_core.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 3345c945262f..f1dfe53515fb 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2321,6 +2321,14 @@ static int musb_resume(struct device *dev)
schedule_delayed_work(&musb->finish_resume_work,
msecs_to_jiffies(20));
}
+
+ /*
+ * 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);
return 0;
}
--
2.1.3
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