[+cc linux-pci]

On Thu, Apr 02, 2020 at 11:23:27PM +0300, Andy Shevchenko wrote:

On Thu, Apr 2, 2020 at 11:16 PM Bjorn Helgaas [off-list ref] wrote:

quoted

On Thu, Apr 02, 2020 at 09:33:46PM +0300, Andy Shevchenko wrote:

quoted

On Thu, Apr 2, 2020 at 6:52 PM Vaibhav Gupta [off-list ref] wrote:

quoted

Convert the legacy callback .suspend() and .resume()
to the generic ones.

Thank you for the patch.

Rather then doing this I think the best approach is to unify gpio-pch
and gpio-ml-ioh together.
Under umbrella of the task, the clean ups like above are highly
appreciated.

I'd be all in favor of that, but what Vaibhav is working toward is
eliminating use of legacy PM in PCI drivers.  I think unifying drivers
is really out of scope for that project.

If you'd rather leave gpio-ml-ioh.c alone for now, I suggest that
Vaibhav move on to other PCI drivers that use legacy PM.  If we
convert all the others away from legacy PM and gpio-ml-ioh.c is the
only one remaining, then I guess we can revisit this :)

Then skip this driver for good.

quoted

Or, maybe converting gpio-ml-ioh.c now, along the lines of
226e6b866d74 ("gpio: pch: Convert to dev_pm_ops"), would be one small
step towards the eventual unification, by making gpio-pch and
gpio-ml-ioh a little more similar.

I think it will delay the real work here (very old code motivates
better to get rid of it then semi-fixed one).

With respect, I think it is unreasonable to use the fact that
gpio-ml-ioh and gpio-pch should be unified to hold up the conversion
of gpio-ml-ioh to generic power management.

I do not want to skip gpio-ml-ioh for good, because it is one of the
few remaining drivers that use the legacy PCI PM interfaces.  We are
very close to being able to remove a significant amount of ugly code
from the PCI core.

gpio-ml-ioh and gpio-pch do look quite similar, and no doubt it would
be great to unify them.  But without datasheets or hardware to test,
that's not a trivial task, and I don't think that burden should fall
on anyone who wants to make any improvements to these drivers.

Another alternative would be to remove legacy PCI PM usage
(ioh_gpio_suspend() and ioh_gpio_resume()) from gpio-ml-ioh.  That
would mean gpio-ml-ioh wouldn't support power management at all, which
isn't a good thing, but maybe it would be even more motivation to
unify it with gpio-pch (which has already been converted by
226e6b866d74 ("gpio: pch: Convert to dev_pm_ops"))?

Bjorn