Messages in this thread | | | Date | Mon, 28 Oct 2019 18:28:59 +0200 | From | Andy Shevchenko <> | Subject | Re: [PATCH 0/2] add regulator driver and mfd cell for Intel Cherry Trail Whiskey Cove PMIC |
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On Mon, Oct 28, 2019 at 02:26:21PM +0100, Hans de Goede wrote: > On 28-10-2019 13:45, Mark Brown wrote: > > On Mon, Oct 28, 2019 at 02:41:46PM +0200, Adrian Hunter wrote: > > > On 25/10/19 10:55 AM, Andy Shevchenko wrote: > > > > > > Since it's about UHS/SD, Cc to Adrian as well. > > > > > My only concern is that the driver might conflict with ACPI methods trying > > > to do the same thing, e.g. there is one ACPI SDHC instance from GPDWin DSDT > > > with code like this: > > Oh, right that is a very good point. > > > That's certainly what's idiomatic for ACPI (though machine specific > > quirks are too!). The safe thing to do would be to only register the > > supply on systems where we know there's no ACPI method. > > Right, so as I mentioned before Andrey told me about the evaluation > board he is using I was aware of only 3 Cherry Trail devices using > the Whiskey Cove PMIC. The GPD win, the GPD pocket and the Lenovo > Yoga book. I've checked the DSDT of all 3 and all 3 of them offer > voltage control through the Intel _DSM method for voltage control. > > I've also actually tested this on the GPD win and 1.8V signalling > works fine there without needing Andrey's patch. > > So it seems that Andrey's patch should only be active on his > dev-board, as actual production hardware ships with the _DSM method. > > I believe that the best solution is for the Whiskey Cove MFD driver: > drivers/mfd/intel_soc_pmic_chtwc.c > > To only register the new cell on Andrey's evaluation board model > (based in a DMI match I guess). Another option would be to do > the DMI check in the regulator driver, but that would mean > udev will needlessly modprobe the regulator driver on production > hardware, so doing it in the MFD driver and not registering the cell > seems best,
I'm wondering if we can upgrade DSDT to provide _DSM for Aero platform.
-- With Best Regards, Andy Shevchenko
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