Hi Marek,
On Mon, Jun 11, 2018 at 5:26 PM Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
> On 06/11/2018 04:30 PM, Geert Uytterhoeven wrote:
> > On Mon, Jun 11, 2018 at 4:19 PM Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
> >> On 06/11/2018 04:10 PM, Geert Uytterhoeven wrote:
> >>> On Mon, Jun 11, 2018 at 4:04 PM Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
> >>>> On 06/11/2018 03:49 PM, Geert Uytterhoeven wrote:
> >>>>> On Mon, Jun 11, 2018 at 3:39 PM Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
> >>>>>> On 06/11/2018 03:03 PM, Geert Uytterhoeven wrote:
> >>>>>>> On Mon, Jun 11, 2018 at 2:15 PM Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
> >>>>>>>> On 06/11/2018 11:56 AM, Geert Uytterhoeven wrote:
> >>>>>>>>> On Mon, Jun 4, 2018 at 7:59 PM Marek Vasut <marek.vasut@xxxxxxxxx> 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.
> >>
> >> But wait, since we control which machines this code runs on , can't we
> >> assure they have valid DTs ? This situation with invalid DT starts to
> >> look a bit hypothetical to me.
> >
> > That assumes you keep the list of machines to check, and don't want to fix the
> > issue automatically when detected (on any R-Car Gen2 or RZ/G1 platform, so
> > you still need to check for r8a779[0-4] and r8a774[23457]).
>
> Yes, I want to keep a list of machines to check, to be _sure_ some
> machine doesn't randomly blow up.
Just checking for the presence of a "renesas,irqc" node should be sufficient.
Using that node would also get rid of the hardcoded IRQC_BASE address.
Note that the code assumes IRQ2. If another IRQ is used, that won't harm
much though (as in: if it didn't blow up before, it won't blow up now).
> > Anyway, as we care about booting old DTBs on new kernels (for a while), we
> > have a few more release cycles to bikeshed ;-)
>
> I was about to ask if this patch then makes any sense or not.
Sure. Less hard-coding is always better.
Especially if it means we can make it work on more machines automatically :-)
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
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
