On Mon, Dec 19, 2022 at 11:48:51AM +0200, Andy Shevchenko wrote: > On Mon, Dec 19, 2022 at 09:51:43AM +0100, Luca Ceresoli wrote: > > On Sun, 11 Dec 2022 18:55:39 +0200 Laurent Pinchart wrote: > > > On Thu, Dec 08, 2022 at 12:39:59PM +0200, Tomi Valkeinen wrote: > > ... > > > > This may be a stupid question, but couldn't you instead use the > > > BUS_NOTIFY_ADD_DEVICE and BUS_NOTIFY_DEL_DEVICE bus notifiers ? > > > > I'm not sure they would be the correct tool for this task. Bus > > notifiers inform about new events on the 'struct bus_type, i.e. any > > event on the global i2c bus type. In the i2c world this means being > > notified about new _adapters_, which is exactly what > > drivers/i2c/i2c-dev.c does. > > > > Here, however, we need to be informed about new _clients_ being added > > under a specific adapter. > > This is for example exactly what ACPI integration in I2C framework does. But... > > > I'm not sure whether the bus notifiers can > > inform about new clients in addition of new adapters, but they at least > > seem unable to provide per-adapter notification. > > ...personally I don't like notifiers, they looks like overkill for this task. But isn't this patch essentially implementing a custom notification system ? If we need notifiers, why would it be better to add an ad-hoc API for I2C instead of using bus notifiers ? > > Does that seem correct? -- Regards, Laurent Pinchart