Messages in this thread | | | Subject | Re: [RFC PATCH 1/2] ACPI / PNP: Don't add "enumeration_by_parent" devices | From | John Garry <> | Date | Mon, 30 Apr 2018 10:35:13 +0100 |
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>>>> So we using the mfd_cell to match child devices using _HID. At a glance, I >>>> don't actually see other drivers to use mfd_cell_acpi_match.pnpid . >>>> >>>> Anyway we don't use static tables as we need to update the resources of the >>>> cell dynamically. However I do look at a driver like intel_quark_i2c_gpio.c, >>>> and this dynamically modifies the value of global mfd_cell array here: >>>> https://elixir.bootlin.com/linux/latest/source/drivers/mfd/intel_quark_i2c_gpio.c#L266 >>>> >>>> I know the cell array is only used at probe time, but this did not look to >>>> be good standard practice to me. >>> >>> Lots of drivers do this to supply dynamic data. If there is no other >>> sane way of providing such data, it's fine to do. Although each >>> situation should be dealt with on a case-by-case basis. >>> >> >> Hi Lee, >> >> Thanks for your input. >> >> I do see others drivers which use dynamic mem for the mfd_cells (like >> cros_ec_dev.c), so what we're doing in this driver already is not totally >> unchartered territory. But creating the MFD cells from the ACPI table could >> be ... > > Right. I don't normally like mixing platform data technologies (MFD, > ACPI and DT). I normally NACK patches which take information from > Device Tree and populate MFD cells with it. ACPI would be the same I > guess.
Oh, well that is what we have in this driver. So what's the preferred approach? Just not use MFD model at all if ACPI/DT needs to be scanned for data to create the cells?
Thanks, John
> >> Anyway, I'll cc you in my next patchset and maybe you can kindly check it. >> >
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