[PATCH V3] ARM: shmobile: Rework the PMIC IRQ line quirk

[geert@linux-m68k.org (Geert Uytterhoeven)]

Hi Marek,

On Mon, Jun 11, 2018 at 4:04 PM Marek Vasut <marek.vasut@gmail.com> wrote:
> On 06/11/2018 03:49 PM, Geert Uytterhoeven wrote:
> > On Mon, Jun 11, 2018 at 3:39 PM Marek Vasut <marek.vasut@gmail.com> wrote:
> >> On 06/11/2018 03:03 PM, Geert Uytterhoeven wrote:
> >>> On Mon, Jun 11, 2018 at 2:15 PM Marek Vasut <marek.vasut@gmail.com> wrote:
> >>>> On 06/11/2018 11:56 AM, Geert Uytterhoeven wrote:
> >>>>> On Mon, Jun 4, 2018 at 7:59 PM Marek Vasut <marek.vasut@gmail.com> wrote:
> >>>>>> Rather than hard-coding the quirk topology, which stopped scaling,
> >>>>>> parse the information from DT. The code looks for all compatible
> >>>>>> PMICs -- da9036 and da9210 -- and checks if their IRQ line is tied
> >>>>>> to the same pin. If so, the code sends a matching sequence to the
> >>>>>> PMIC to deassert the IRQ.
> >
> >>>>>> +               ret = of_property_read_u32(np, "reg", &addr);
> >>>>>> +               if (ret)
> >>>>>> +                       return ret;
> >>>>>
> >>>>> I think it's safer to skip this entry and continue, after calling
> >>>>> kfree(quirk), of course.
> >>>>>
> >>>>>> +
> >>>>>> +               quirk->id = id;
> >>>>>> +               quirk->i2c_msg.addr = addr;
> >>>>>> +               quirk->shared = false;
> >>>>>> +
> >>>>>> +               ret = of_irq_parse_one(np, 0, &quirk->irq_args);
> >>>>>> +               if (ret)
> >>>>>> +                       return ret;
> >>>>>
> >>>>> kfree(quirk) and continue...
> >>>>
> >>>> I wonder if it shouldn't rather free the entire list and abort ?
> >>>
> >>> "Be strict when sending, be liberal when receiving."
> >>
> >> Meaning ? I think "the language barrier is protecting me" (TM)
> >
> > Do the best you can, given the buggy DT you received.
> > I.e. don't fail completely, just ignore the bad device node, and continue.
>
> But if you ignore node, you might as well ignore one which is shared and
> then the system crashes due to IRQ storm anyway. So hum, what can we do ?

Correct. If it's a critical node, it will crash regardless.
If it's a non-critical node, you have the choice between aborting and crashing,
or ignoring and keeping the system alive. Your call.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds