On Wed, Sep 10, 2025 at 10:21:58AM +0200, Jörg Sommer wrote:
> Yibo Dong schrieb am Mi 10. Sep, 14:08 (+0800):
> > On Tue, Sep 09, 2025 at 01:58:22PM -0700, Jakub Kicinski wrote:
> > > On Tue, 9 Sep 2025 19:59:11 +0530 Anwar, Md Danish wrote:
> > > > > +int mucse_mbx_sync_fw(struct mucse_hw *hw)
> > > > > +{
> > > > > + int try_cnt = 3;
> > > > > + int err;
> > > > > +
> > > > > + do {
> > > > > + err = mucse_mbx_get_info(hw);
> > > > > + if (err == -ETIMEDOUT)
> > > > > + continue;
> > > > > + break;
> > > > > + } while (try_cnt--);
> > > > > +
> > > > > + return err;
> > > > > +}
> > > >
> > > > There's a logical issue in the code. The loop structure attempts to
> > > > retry on ETIMEDOUT errors, but the unconditional break statement after
> > > > the if-check will always exit the loop after the first attempt,
> > > > regardless of the error. The do-while loop will never actually retry
> > > > because the break statement is placed outside of the if condition that
> > > > checks for timeout errors.
> > >
> >
> > What is expected is 'retry on ETIMEDOUT' and 'no retry others'.
> > https://lore.kernel.org/netdev/a066746c-2f12-4e70-b63a-7996392a9132@xxxxxxx/
> >
> > > The other way around. continue; in a do {} while () look does *not*
> > > evaluate the condition. So this can loop forever.
> > >
> >
> > Maybe I can update like this ?
> >
> > int mucse_mbx_sync_fw(struct mucse_hw *hw)
> > {
> > int try_cnt = 3;
> > int err;
> >
> > do {
> > err = mucse_mbx_get_info(hw);
> > if (err != -ETIMEDOUT)
> > break;
> > /* only retry with ETIMEDOUT, others just return */
> > } while (try_cnt--);
> >
> > return err;
> > }
>
> How about something like this?
>
> int mucse_mbx_sync_fw(struct mucse_hw *hw)
> {
> for (int try = 3; try; --try) {
> int err = mucse_mbx_get_info(hw);
> if (err != -ETIMEDOUT)
> return err;
> }
>
> return ETIMEDOUT;
> }
>
I think Jakub Kicinski's suggestion is clearer, right?
do {
err = mucse_mbx_get_info(hw);
} while (err == -ETIMEDOUT && try_cnt--);
>
> My 2cent.
>
> Regards Jörg
>
> --
> „Es wurden und werden zu viele sprachlose Bücher gedruckt, nach deren
> schon flüchtiger Lektüre man all die Bäume um Vergebung bitten möchte,
> die für den Schund ihr Leben lassen mussten.“ (Michael Jürgs,
> Seichtgebiete – Warum wir hemmungslos verblöden)
Thanks for your feedback.
