[PATCH v4 1/4] cmd: bind: Add unbind command with driver filter

[Marek Vasut]

On 8/4/23 17:01, Tom Rini wrote:
> On Fri, Aug 04, 2023 at 04:42:13PM +0200, Marek Vasut wrote:
>> On 8/4/23 09:00, Miquel Raynal wrote:
>>> Hi Marek,
>>>
>>> marex at denx.de wrote on Wed,  2 Aug 2023 14:46:54 +0200:
>>>
>>>> Extend the driver core to perform lookup by both OF node and driver
>>>> bound to the node. Use this to look up specific device instances to
>>>> unbind from nodes in the unbind command. One example where this is
>>>> needed is USB peripheral controller, which may have multiple gadget
>>>> drivers bound to it. The unbind command has to select that specific
>>>> gadget driver instance to unbind from the controller, not unbind the
>>>> controller driver itself from the controller.
>>>>
>>>> USB ethernet gadget usage looks as follows with this change. Notice
>>>> the extra 'usb_ether' addition in the 'unbind' command at the end.
>>>> "
>>>> bind /soc/usb-otg at 49000000 usb_ether
>>>> setenv ethact usb_ether
>>>> setenv loadaddr 0xc2000000
>>>> setenv ipaddr 10.0.0.2
>>>> setenv serverip 10.0.0.1
>>>> setenv netmask 255.255.255.0
>>>> tftpboot 0xc2000000 10.0.0.1:test.file
>>>> unbind /soc/usb-otg at 49000000 usb_ether
>>>
>>> This extra parameter does not seem to work on the BBBW. I cannot select
>>> the "usb_ether" driver like you do.
>>>
>>> Good news though, I am now able to use fastboot, but it is not
>>> straightforward:
>>>
>>> Here is my sequence right after the boot (reducing the dm tree output
>>> to the usb nodes for clarity):
>>>
>>> => dm tree
>>>    misc          0  [ + ]   ti-musb-wrapper       |   |-- usb at 47400000
>>>    usb           0  [ + ]   ti-musb-peripheral    |   |   |-- usb at 47401000
>>>    ethernet      1  [ + ]   usb_ether             |   |   |   `-- usb_ether
>>>    bootdev       3  [   ]   eth_bootdev           |   |   |       `-- usb_ether.bootdev
>>>    usb           0  [   ]   ti-musb-host          |   |   `-- usb at 47401800
>>> => fastboot usb 0
>>> couldn't find an available UDC
>>> g_dnl_register: failed!, error: -19
>>
>> That is expected and not a bug, since the beagle explicitly binds USB
>> ethernet to MUSB gadget in board file, which is legacy deprecated way.
> 
> So, we should do away with, probably all of arch_misc_init() in
> arch/arm/mach-omap2/am33xx/board.c for the non-SPL case.

Yes

>>> exit not allowed from main input shell.
>>> => unbind /ocp/usb at 47400000/usb at 47401000 usb_ether
>>
>> Does
>>
>> => unbind ethernet 0
>>
>> work ?
>>
>> If so, 1/4 in this series can be skipped altogether.
>>
>> You likely won't even need the rebinding of ti-musb-peripheral anymore.
>>
>>> Cannot find a device with path /ocp/usb at 47400000/usb at 47401000
>>> => unbind /ocp/usb at 47400000/usb at 47401000
>>> => dm tree
>>>    misc          0  [ + ]   ti-musb-wrapper       |   |-- usb at 47400000
>>>    usb           0  [   ]   ti-musb-host          |   |   `-- usb at 47401800
>>> => fastboot usb 0
>>> => bind /ocp/usb at 47400000/usb at 47401000 ti-musb-peripheral
>>> => dm tree
>>>    misc          0  [ + ]   ti-musb-wrapper       |   |-- usb at 47400000
>>>    usb           0  [   ]   ti-musb-host          |   |   |-- usb at 47401800
>>>    usb           0  [   ]   ti-musb-peripheral    |   |   `-- usb at 47401000
>>> => fastboot usb 0
>>> musb-hdrc: peripheral reset irq lost!
>>> # works! (the irq-related line above as always been there)
>>>
>>> So now, how do we make this process easy/understandable?
>>
>> What would be your proposal ?
> 
> Well, what's needed / is it possible to get to the point where we don't
> _need_ to call bind/unbind for each of these cases? Is there something
> we're supposed to be setting in the DT that we aren't?

You do need to unbind the ethernet before using fastboot, always, with 
the 'unbind ethernet 0', you dont need the peripheral unbind/rebind 
part, so it should behave like before.