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From: Felipe Balbi <felipe.balbi@linux.intel.com>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: "Du\, Changbin" <changbin.du@intel.com>, Al Viro <viro@zeniv.linux.org.uk>,
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Subject: RE: [PATCH] usb: gadget: f_fs: report error if excess data received
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Date: Mon, 16 May 2016 15:57:44 +0300
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Hi,

Alan Stern <stern@rowland.harvard.edu> writes:
> On Fri, 13 May 2016, Felipe Balbi wrote:
>
>> We deliver to userspace the part userspace requested, right? So that's
>> okay. The USB details WRT e.g. babble or host trying to send more data
>> than expected, needs to be handled within the kernel.
>
> The point is that you don't know whether the host sent more data than
> expected.  All you know is that the host sent more data than the user
> asked the kernel for -- but maybe the user didn't ask for all the data
> that he expected.  Maybe the user wanted to retrieve the full set of
> data using two read() system calls.

right, but that just means we need to buffer the data instead of bailing
out of the first read() completely.

=2D-=20
balbi

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