Hi Wolfram, On Tue, Jan 16, 2018 at 3:11 PM, Javier Martinez Canillas <javierm@xxxxxxxxxx> wrote: > Hello Dmitry, > > On 01/16/2018 02:55 PM, Dmitry Mastykin wrote: >> On Sun, 3 Dec 2017 22:40:50 +0100, Javier Martinez Canillas >> <javierm@xxxxxxxxxx> wrote: >> >>> The buses should honor the firmware interface used to register the device, >>> but the I2C core reports a MODALIAS of the form i2c:<device> even for I2C >>> devices registered via OF. >>> >>> This means that user-space will never get an OF stype uevent MODALIAS even >>> when the drivers modules contain aliases exported from both the I2C and OF >>> device ID tables. For example, an Atmel maXTouch Touchscreen registered by >>> a DT node with compatible "atmel,maxtouch" has the following module alias: >>> >>> $ cat /sys/class/i2c-adapter/i2c-8/8-004b/modalias >>> i2c:maxtouch >>> >>> So udev won't be able to auto-load a module for an OF-only device driver. >>> Many OF-only drivers duplicate the OF device ID table entries in an I2C ID >>> table only has a workaround for how the I2C core reports the module alias. >>> >>> This patch changes the I2C core to report an OF related MODALIAS uevent if >>> the device was registered via OF. So for the previous example, after this >>> patch, the reported MODALIAS for the Atmel maXTouch will be the following: >>> >>> $ cat /sys/class/i2c-adapter/i2c-8/8-004b/modalias >>> of:NtrackpadT<NULL>Catmel,maxtouch >>> >>> NOTE: This patch may break out-of-tree drivers that were relying on this >>> behavior, and only had an I2C device ID table even when the device >>> was registered via OF. There are no remaining drivers in mainline >>> that do this, but out-of-tree drivers have to be fixed and define >>> a proper OF device ID table to have module auto-loading working. >>> >> >> Hello Javier, >> thank you for your patch! >> > > Thanks a lot for testing! > > Hopefully Wolfram will review/merge this soon, otherwise in the meantime drivers > are going to add I2C device ID tables just as a workaround or new drivers won't > include a OF device ID tables since these aren't really required today. > Another gentle ping for this. Best regards, Javier
