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From: Peter Maydell <peter.maydell@linaro.org>
Date: Mon, 11 Mar 2019 16:25:05 +0000
Message-ID: <CAFEAcA9sx64kcz=wOqeBwGg0YJc-xO-K5yNkoSC8uuCqNF_FYA@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Subject: Re: [Qemu-devel] [PATCH] usb-mtp: fix return status of delete
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To: Bandan Das <bsd@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>, QEMU Developers <qemu-devel@nongnu.org>

On Mon, 11 Mar 2019 at 16:14, Bandan Das <bsd@redhat.com> wrote:
>
> Peter Maydell <peter.maydell@linaro.org> 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