Re: [PATCH v4 3/4] usb: ffs: check quirk to pad epout buf size whennot aligned to maxpacketsize

From: David Cohen
Date: Fri Nov 08 2013 - 12:59:50 EST


Hi Michal,

On 11/08/2013 04:23 AM, Michal Nazarewicz wrote:
On Thu, Nov 07 2013, Alan Stern wrote:
What happens if the userspace daemon writes to epfile but the host
changes the config or altsetting before all the data can be sent? Does
the remaining data get flushed?

Each read and write is mapped to a single request, so the usual.

I'm still a little unclear on this. Disabling the function ought to
have much the same effect as changing the config or altsetting: Writes
to endpoint files should be flushed and reads should be terminated.
Otherwise you would end up sending stale data to the host or reading
data that the daemon isn't prepared for.

You may have a point here. I'll try to prepare a patch over the weekend.

It looks like our patches are going to have dependence.
If you send yours this weekend, I'll wait to send new version of this
patch of mine on top of yours.

Br, David Cohen
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