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SubjectRe: [PATCH] pinctrl: intel: save HOSTSW_OWN register over suspend/resume
On Tue, Apr 2, 2019 at 7:58 PM Andy Shevchenko
<andriy.shevchenko@intel.com> wrote:
> > + base = community->regs + community->hostown_offset;
> > + for (gpp = 0; gpp < community->ngpps; gpp++) {
> > + if (communities[i].hostown[gpp] &&
> > + communities[i].hostown[gpp] != readl(base
> > + gpp * 4)) {
> > + writel(communities[i].hostown[gpp],
> > base + gpp * 4);
> > + dev_warn(dev, "hostown changed after resume\n");
> > + dev_dbg(dev, "restored hostown %d/%u
> > %#08x\n", i, gpp,
> > + readl(base + gpp * 4));
> > + }
> > + }
>
> Instead you may need to loop over each pin in the part of the group related to
> one 32-bit HOSTSW_OWN register (i.e. 8, see PADOWN_*() macros in the driver),
> check if it's requested and break a loop. If loop index is off-by-one a limit,
> nothing to do, otherwise restore hostown register.
>
> More pedantic approach is to collect the mask inside the loop and apply it.
>
> The check function name is gpiochip_is_requested().
>
> (One of Intel's drivers which is using that at ->resume() is
> drivers/gpio/gpio-lynxpoint.c)
>
> P.S. I prefer pedantic approach. The simplification one is showed in order to
> give you an idea.
>
> --
> With Best Regards,
> Andy Shevchenko
>
>

Thanks for your great comment. I remove the useless hostown save function
and make the following change in ->resume() to detect and restore the abnormal
HOSTSW_OWN. Please help comment if there're still problems. Thanks.

@@ -1588,6 +1600,29 @@ int intel_pinctrl_resume(struct device *dev)
dev_dbg(dev, "restored mask %d/%u %#08x\n", i, gpp,
readl(base + gpp * 4));
}
+
+ base = community->regs + community->hostown_offset;
+ for (gpp = 0; gpp < community->ngpps; gpp++) {
+ const struct intel_padgroup *padgrp =
&community->gpps[i];
+ unsigned int requested = 0;
+ int j;
+
+ if (padgrp->gpio_base < 0)
+ continue;
+
+ for (j = 0; j < padgrp->size; j++)
+ if
(gpiochip_is_requested(&pctrl->chip, padgrp->gpio_base + j))
+ requested |= BIT(j);
+
+ if (requested) {
+ if (communities[i].hostown[gpp] !=
readl(base + gpp * 4)) {
+
writel(communities[i].hostown[gpp], base + gpp * 4);
+ dev_warn(dev, "hostown been
changed during resume\n");
+ dev_dbg(dev, "restored hostown
%d/%u %#08x\n", i, gpp,
+ readl(base + gpp * 4));
+ }
+ }
+ }
}

return 0;

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