Re: [PATCH net 2/2] r8152: rx descriptor check

[David Miller]

From: Hayes Wang <hayeswang@xxxxxxxxxxx>
Date: Mon, 14 Nov 2016 07:23:51 +0000

> Mark Lord [mailto:mlord@xxxxxxxxx]
>> Sent: Monday, November 14, 2016 4:34 AM
> [...]
>> Perhaps the driver
>> is somehow accessing the buffer space again after doing usb_submit_urb()?
>> That would certainly produce this kind of behaviour.
> 
> I don't think so. First, the driver only read the received buffer.
> That is, the driver would not change (or write) the data. Second,
> The driver would lose the point address of the received buffer
> after submitting the urb to the USB host controller, until the
> transfer is completed by the USB host controller. That is, the
> driver doesn't how to access the buffer after calling usb_submit_urb().

This is why it's most likely some DMA implementation issue or similar.