[PATCH] time: Fix get_ticks being non-monotonic

[Simon Glass]

Hi Sean,

On Tue, 1 Sep 2020 at 13:56, Sean Anderson <seanga2 at gmail.com> wrote:
>
> get_ticks does not always succeed. Sometimes it can be called before the
> timer has been initialized. If it does, it returns a negative errno.
> This causes the timer to appear non-monotonic, because the value will
> become much smaller after the timer is initialized.
>
> No users of get_ticks which I checked handle errors of this kind. Further,
> functions like tick_to_time mangle the result of get_ticks, making it very
> unlikely that one could check for an error without suggesting a patch such
> as this one.
>
> This patch changes get_ticks to always return 0 when there is an error.
> 0 is the least unsigned integer, ensuring get_ticks appears monotonic. This
> has the side effect of time apparently not passing until the timer is
> initialized. However, without this patch, time does not pass anyway,
> because the error value is likely to be the same.
>
> Fixes: c8a7ba9e6a5
> Signed-off-by: Sean Anderson <seanga2 at gmail.com>
> ---
>
>  lib/time.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Would it be better to panic so people can fix the bug?

Regards,
Simon