On Thu, Nov 12, 2020 at 4:57 PM Jason Gunthorpe <jgg@xxxxxxxxxx> wrote:
>
> On Mon, Oct 26, 2020 at 10:12:30PM +0100, Arnd Bergmann wrote:
> > From: Arnd Bergmann <arnd@xxxxxxxx>
> >
> > gcc points out a suspicious mixing of enum types in a function that
> > converts from MTHCA_OPCODE_* values to IB_WC_* values:
> >
> > drivers/infiniband/hw/mthca/mthca_cq.c: In function 'mthca_poll_one':
> > drivers/infiniband/hw/mthca/mthca_cq.c:607:21: warning: implicit conversion from 'enum <anonymous>' to 'enum ib_wc_opcode' [-Wenum-conversion]
> > 607 | entry->opcode = MTHCA_OPCODE_INVALID;
> >
> > Nothing seems to ever check for MTHCA_OPCODE_INVALID again, no
> > idea if this is meaningful, but it seems harmless as it deals
> > with an invalid input.
> >
> > Add a cast to suppress the warning.
> >
> > Fixes: 2a4443a69934 ("[PATCH] IB/mthca: fill in opcode field for send completions")
> > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> > drivers/infiniband/hw/mthca/mthca_cq.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/infiniband/hw/mthca/mthca_cq.c b/drivers/infiniband/hw/mthca/mthca_cq.c
> > index c3cfea243af8..319b8aa63f36 100644
> > +++ b/drivers/infiniband/hw/mthca/mthca_cq.c
> > @@ -604,7 +604,7 @@ static inline int mthca_poll_one(struct mthca_dev *dev,
> > entry->byte_len = MTHCA_ATOMIC_BYTE_LEN;
> > break;
> > default:
> > - entry->opcode = MTHCA_OPCODE_INVALID;
> > + entry->opcode = (u8)MTHCA_OPCODE_INVALID;
> > break;
>
> This code is completely bogus, sigh
>
> Is this OK as far as the warning goes?
Yes, I'm sure your patch fixes it and it makes more sense than my version.
Acked-by: Arnd Bergmann <arnd@xxxxxxxx>
