Re: [PATCH] usb: gadget: f_fs: report error if excess data received

[Michal Nazarewicz]

On Wed, May 18 2016, Felipe Balbi wrote:
> we've been through this before. This needs to be done at the gadget
> layer. Gadget driver can over-allocate ahead of time if
> gadget->quirk_ep_out_aligned_size is true, then we avoid memcpy() at
> the UDC driver level.

Right, all right, so letâs look at it from a regular USB function point
of view.  If a USB function allocates a request which is not aligned,
UDC will align the buffer and *drop* excess data.  Seeing how ugly
f_fsâs code is becoming, Iâm now leaning to letting to f_fs do the same
thing: if user space makes an unaligned read, f_fs aligns the buffer and
then drops excess data.

Any arguments for f_fs to not drop the data apply to UDC, so they should
behave identically.

-- 
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