Re: [PATCH] usb: musb: core: Disable the Interrupts till BABBLE is fully handled

From: Felipe Balbi
Date: Tue Nov 18 2014 - 16:17:29 EST

On Fri, Nov 14, 2014 at 01:54:46PM +0530, George Cherian wrote:
> Disable the MUSB interrupts till MUSB is recovered fully from BABBLE
> condition. There are chances that we could get multiple interrupts
> till the time the babble recover work gets scheduled. Sometimes
> this could even end up in an endless loop making MUSB itself unusable.
> Reported-by: Felipe Balbi <balbi@xxxxxx>
> Signed-off-by: George Cherian <george.cherian@xxxxxx>

while this helps the situation it doesn't solve the problem I'm having
with testusb on BBB when host port is connected to peripheral port on
the same BBB.

I still have:

# ./testusb -t 13 -c 10 -s 2048 -a
unknown speed /dev/bus/usb/002/004 0
[ 114.811407] usbtest 2-1:3.0: set altsetting to 0 failed, -71
/dev/bus/usb/002/004 test 13 --> 71 (error 71)
[ 114.862387] CAUTION: musb: Babble Interrupt Occurred
[ 114.868132] usb 2-1: USB disconnect, device number 4
[ 114.961491] musb-hdrc Restarting MUSB to recover from Babble
[ 115.430829] usb 2-1: new high-speed USB device number 5 using musb-hdrc
[ 115.573471] zero gadget: high-speed config #3: source/sink
[ 115.584014] usbtest 2-1:3.0: Linux gadget zero
[ 115.588682] usbtest 2-1:3.0: high-speed {control in/out bulk-in bulk-out} tests (+alt)

I think the driver is mis-detecting Babble. A babble only occurs when
the device side tries to move data without the host asking for anything.


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