Messages in this thread | | | Subject | Re: [alsa-devel] [PATCH v5 09/17] soundwire: intel: remove platform devices and use 'Master Devices' instead | From | Pierre-Louis Bossart <> | Date | Mon, 13 Jan 2020 09:22:15 -0600 |
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On 1/12/20 11:18 PM, Vinod Koul wrote: > On 10-01-20, 10:08, Pierre-Louis Bossart wrote: >> >>>>> The "big" difference is that probe is called by core (asoc) and not by >>>>> driver onto themselves.. IMO that needs to go away. >>>> >>>> What I did is not different from what existed already with platform devices. >>>> They were manually created, weren't they? >>> >>> Manual creation of device based on a requirement is different, did I ask >>> you why you are creating device :) >>> >>> I am simple asking you not to call probe in the driver. If you need >>> that, move it to core! We do not want these kind of things in the >>> drivers... >> >> What core are you talking about? > > soundwire core ofcourse! IMO All that which goes into soundwire-bus-objs is > considered as soundwire core part and rest are drivers intel, qc, so on! This master code was added to the bus: v v soundwire-bus-objs := bus_type.o bus.o master.o slave.o mipi_disco.o stream.o obj-$(CONFIG_SOUNDWIRE) += soundwire-bus.o
and the API is also part of the sdw.h include file. That seems to meet exactly what you describe above, no?
git grep sdw_master_device_add (reformatted output)
drivers/soundwire/intel_init.c: md = sdw_master_device_add(&intel_sdw_driver,
drivers/soundwire/master.c: *sdw_master_device_add(struct sdw_master_driver *driver,
drivers/soundwire/master.c: EXPORT_SYMBOL_GPL(sdw_master_device_add);
include/linux/soundwire/sdw.h: *sdw_master_device_add(struct sdw_master_driver *driver,
So, what exactly is the issue?
We are not 'calling the probe in the [Intel] driver' as you state it, we use a SoundWire core API which in turn will create a device. The device core takes care of calling the probe, see the master.c code which is NOT Intel-specific.
>> >> The SOF intel driver needs to create a device, which will then be bound with >> a SoundWire master driver. >> >> What I am doing is no different from what your team did with >> platform_register_device, I am really lost on what you are asking. > > Again repeating myself, you call an API to do that is absolutely fine, > but we don't do that in drivers or open code these things That is still quite unclear, what 'open-coding' are you referring to?
I am starting to wonder if you missed the addition of the master functionality in the previous patch:
[PATCH v5 08/17] soundwire: add initial definitions for sdw_master_device
What this patch 9 does is call the core-defined API and implement the intel-specific master driver.
> >>>>>> FWIW, the implementation here follows what was suggested for Greybus 'Host >>>>>> Devices' [1] [2], so it's not like I am creating any sort of dangerous >>>>>> precedent. >>>>>> >>>>>> [1] >>>>>> https://elixir.bootlin.com/linux/latest/source/drivers/greybus/es2.c#L1275 >>>>>> [2] https://elixir.bootlin.com/linux/latest/source/drivers/greybus/hd.c#L124 >>>>> >>>>> And if you look closely all this work is done by core not by drivers! >>>>> Drivers _should_ never do all this, it is the job of core to do that for >>>>> you. >>>> >>>> Please look at the code again, you have a USB probe that will manually call >>>> the GreyBus device creation. >>>> >>>> static int ap_probe(struct usb_interface *interface, >>>> const struct usb_device_id *id) >>>> { >>>> hd = gb_hd_create(&es2_driver, &udev->dev, >>>> >>>> >>>> static struct usb_driver es2_ap_driver = { >>>> .name = "es2_ap_driver", >>>> .probe = ap_probe, <<< code above >>>> .disconnect = ap_disconnect, >>>> .id_table = id_table, >>>> .soft_unbind = 1, >>>> }; >>> >>> Look closely the driver es2 calls into greybus core hd.c and gets the >>> work done, subtle but a big differances in the approaches.. >> >> I am sorry, I have absolutely no idea what you are referring to. >> >> The code I copy/pasted here makes no call to the greybus core, it's ap_probe >> -> gb_hd_create. No core involved. If I am mistaken, please show me what I >> got wrong. > > 1. es2_ap_driver is host controller driver > > 2. gb_hd_create() is an API provided by greybus core!
same in my code...
> > es2 driver doesn't open code creation like you are doing in intel driver, > it doesn't call probe on its own, greybus does that > > This is very common pattern in linux kernel subsytems, drivers dont do > these things, the respective subsystem core does that... see about es2 > driver and implementation of gb_hd_create(). See callers of > platform_register_device() and its implementation. > > I don't know how else I can explain this to you, is something wrong in > how I conveyed this info or you... or something else, I dont know!!! the new 'master' functionality is part of the bus code, so please clarify what you see as problematic for the partition.
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