[SLOF] [PATCH 2/3] virtio-serial: Make read and write methods report failure

[Jordan Niethe]

On Mon, Aug 28, 2023 at 5:01 PM Thomas Huth <thuth at redhat.com> wrote:
>
> On 28/08/2023 03.37, Jordan Niethe wrote:
> > From: Kautuk Consul <kconsul at linux.vnet.ibm.com>
> >
> > The read and write methods return as though they were successfully even
>
> I'd scratch "as though they were" from the sentence - that part makes it
> just harder to read IMHO.

Sure.

>
> > if the virtio device is closed (virtiodev is 0) and it is not able to
> > send or receive any characters.
> >
> > Make the read and write methods return 0 to indicate they did not
> > succeed in this case.
> >
> > Signed-off-by: Kautuk Consul <kconsul at linux.vnet.ibm.com>
> > Signed-off-by: Jordan Niethe <jniethe5 at gmail.com>
> > ---
> >   board-qemu/slof/virtio-serial.fs | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/board-qemu/slof/virtio-serial.fs b/board-qemu/slof/virtio-serial.fs
> > index a67a310..41e2e04 100644
> > --- a/board-qemu/slof/virtio-serial.fs
> > +++ b/board-qemu/slof/virtio-serial.fs
> > @@ -67,7 +67,7 @@ virtiodev virtio-serial-init drop
> >   ;
> >
> >   : write ( addr len -- actual )
> > -    virtiodev 0= IF nip EXIT THEN
> > +    virtiodev 0= IF 2drop 0 EXIT THEN
>
> Ok, makes sense!
>
> >       tuck
> >       0 ?DO
> >           dup c@ virtiodev SWAP virtio-serial-putchar
> > @@ -78,7 +78,7 @@ virtiodev virtio-serial-init drop
> >
> >   : read ( addr len -- actual )
> >       0= IF drop 0 EXIT THEN
> > -    virtiodev 0= IF drop 1 EXIT THEN
> > +    virtiodev 0= IF drop 0 EXIT THEN
>
> Ah, ok, here's the 0 ... I'd suggest to use that in the first patch already.

Just wanted to seperate fixing the incorrectly implemented desired
behaviour of commit 8174acd ("virtio-serial: Close device completely")
in which the virtiodev == 0 case returns successfully and changing
that to return unsuccessfully, to check if there was some other
situation Alexey had had in mind for that behaviour.

First patch can be dropped.

>
>   Thomas
>
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