Re: [PATCH] rtc: report time-retrieval errors when updating alarm

From: Alexandre Belloni
Date: Mon Oct 21 2019 - 13:48:14 EST


On 21/10/2019 10:20:08-0700, Brian Norris wrote:
> Hi Alexandre!
>
> On Mon, Oct 21, 2019 at 9:11 AM Alexandre Belloni
> <alexandre.belloni@xxxxxxxxxxx> wrote:
> > On 21/05/2018 09:42:22-0700, Brian Norris wrote:
> > > __rtc_read_time() can fail (e.g., if the RTC uses an unreliable medium).
> > > When it does, we don't report the error, but instead calculate a
> > > 1-second alarm based on the potentially-garbage 'tm' (in practice,
> > > __rtc_read_time() zeroes out the time first, so it's likely to still be
> > > all 0).
> > >
> > > Let's propagate the error instead.
> > >
> >
> > I submitted
> > https://lore.kernel.org/linux-rtc/20191021155631.3342-2-alexandre.belloni@xxxxxxxxxxx/T/#u
> > to solve this after looking at all the implication checking the return
> > value of __rtc_read_time had.
>
> Only about a year and a half late, nice!

I know, right? :) The fact is that this is not a common issue or at
least, I didn't have any report that this was causing real problems in
the field. So it ended up being one of the longest standing patch in
patchwork...

>Fortunately we have a decent
> (albeit time-consuming) process for rebasing our downstream patches in
> Chrome OS kernels...
>

Do you need that patch backported to LTS kernels?


--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com