Messages in this thread | | | From | Bartlomiej Zolnierkiewicz <> | Subject | Re: [PATCH v2 0/5] mfd: Fix platform device ids to avoid probe failure | Date | Mon, 23 Mar 2015 14:11:50 +0100 |
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Hi,
On Monday, March 23, 2015 11:07:18 AM Johan Hovold wrote: > On Fri, Mar 20, 2015 at 08:23:18PM +0100, Bartlomiej Zolnierkiewicz wrote: > > > Commit 6e3f62f0793e ("mfd: core: Fix platform-device id generation") > > changed the way platform device ids are generated from mfd id base and > > cell ids in mfd_add_device(). Unfortunately the change in question > > breaks mfd drivers which are using mfd_add_devices() with mfd id base > > equal to -1 and non-zero cell ids (used to distinguish cells with > > the same name field). The result is that mfd core tries to register > > platform devices with the same name which obviously fails and leads > > to mfd device probe failure. > > First of all, thanks for finding these. I obviously overlooked this > class of drivers when fixing the device-id generation. > > > Changing mfd_add_devices() mfd id base from -1 to 0 and at the same > > time setting proper cell ids for all cells fixes the issue. > > This is however not the right fix. Instead you should be using > PLATFORM_DEVID_AUTO and keep the non-zero cell-ids as is, as this will > allow more than one mfd-device to be registered without resorting to > hacks.
Conversion of a driver to use PLATFORM_DEVID_AUTO changes names of all platform devices registered by the driver. In my patchset I just tried to restore the broken functionality (patch that broke it went in v3.19). I thought that it was the best solution for v3.19 and v4.0-rc4 (then PLATFORM_DEVID_AUTO conversion can be done sometime later, i.e. in v4.1).
> Have a look at wm831x, for example, which offsets the device id base if > a wm831x_num parameter is passed in platform data (non-dt) to allow more > than one device to be registered. Your patch would break this, and still > not provide any other way to have multiple devices in a system.
OK, I see the problem with wm831x driver and will provide v3 of my patchset which would use PLATFORM_DEVID_AUTO for all drivers.
> Your changes would also break da9052, which would no longer allow more > than one device to be registered, something which was already fixed once > by commit b3f6c73db732 ("mfd: da9052-core: Fix platform-device id > collision").
OK, patch #5 should be just dropped.
Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics
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