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Date: Thu, 30 Jul 2015 11:43:53 +0200
From: Hans Petter Selasky <hps@selasky.org>
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To: Svatopluk Kraus <onwahe@gmail.com>, 
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Subject: Re: [RPI-B] [HEADS UP] DWC OTG TX path optimisation for 11-current
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On 07/30/15 11:32, Svatopluk Kraus wrote:
> I do not think that it's problem of smsc driver. The messages are just
> indicator that something else (it's most propably usb disk related) is
> generating big load so other clients on usb are restrained. However,
> when it happens, this big load does not stop even if system is "idle",
> so it looks that it's generated "internally" somewhere. For example,
> it could be a try to recover from some "problems" which never
> recovers.

Hi,

If other USB requests continue working while this is happening, it is a 
bug in the SMSC driver. I see at least the miibus read/write access is 
not sequential. If multiple threads try to access the miibus via 
ifconfig IOCTLs for example, there can be a race which the driver 
doesn't handle.

BTW: "usbdump" will tell the actual USB error code, if any. If the USB 
hardware is responding correctly, it is for sure a driver bug. Else I'll 
investigate.

--HPS