Re: [Qemu-devel] [PATCH] usb-mtp: fix return status of delete

[Peter Maydell]

On Mon, 11 Mar 2019 at 16:14, Bandan Das <address@hidden> wrote:
>
> Peter Maydell <address@hidden> writes:
> > At the moment PARTIAL_DELETE is "ALL_DELETE | READ_ONLY", which
> > doesn't seem like it makes much sense.
> >
>
> Sorry, can you please clarify what doesn't make sense ?

Generally, if you have multiple bits X, Y in a return
value, they should be independent. Sometimes we define
a convenience value Z that's X | Y, but then Z should
have a name that indicates that it's really doing both
X and Y (for instance often a READWRITE constant will
be READ | WRITE). In this case, I don't see why
PARTIAL_DELETE would be a sensible name to indicate
"both ALL_DELETE and also READ_ONLY" -- if we only
partially did a delete why do we set the ALL_DELETE bit ?

It might be useful to take a step back -- what are
the different possible outcomes from this function that
we need to distinguish, and when should we be returning
which outcome?

thanks
-- PMM