[PATCH v3 1/4] cmd: bind: Add unbind command with driver filter

Miquel Raynal miquel.raynal at bootlin.com
Wed Aug 2 09:48:02 CEST 2023


Hi Marek,

marex at denx.de wrote on Wed, 2 Aug 2023 01:07:46 +0200:

> On 8/1/23 20:53, Miquel Raynal wrote:
> > Hi Marek,
> > 
> > marex at denx.de wrote on Mon, 31 Jul 2023 16:40:04 +0200:
> >   
> >> On 7/31/23 16:25, Miquel Raynal wrote:  
> >>> Hi Marek,
> >>>
> >>> marex at denx.de wrote on Mon, 31 Jul 2023 16:08:19 +0200:  
> >>>    >>>> On 7/31/23 15:58, Miquel Raynal wrote:  
> >>>>> Hi Marek,
> >>>>>
> >>>>> marex at denx.de wrote on Mon, 31 Jul 2023 15:50:58 +0200:  
> >>>>>     >>>> On 7/31/23 15:36, Miquel Raynal wrote:  
> >>>>>>> Hi Marek,
> >>>>>>>
> >>>>>>> marex at denx.de wrote on Mon, 31 Jul 2023 13:44:25 +0200:  
> >>>>>>>      >>>> On 7/31/23 11:31, Miquel Raynal wrote:  
> >>>>>>>>> Hi Marek,
> >>>>>>>>>
> >>>>>>>>> marex at denx.de wrote on Sat, 29 Jul 2023 16:57:09 +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
> >>>>>>>>>> "
> >>>>>>>>>>
> >>>>>>>>>> Signed-off-by: Marek Vasut <marex at denx.de>
> >>>>>>>>>> ---  
> >>>>>>>>>
> >>>>>>>>> I am no longer getting wrong pointer dereferences, the SPL is working in
> >>>>>>>>> recovery mode, TFTP "File not found" errors are no longer a problem and
> >>>>>>>>> I did not experience any reset while tftp'ing regular files.
> >>>>>>>>>
> >>>>>>>>> One last remaining request on my side is the need for using fastboot as
> >>>>>>>>> well which does no longer work as-is:  
> >>>>>>>>>       >>> => fastboot usb 0  
> >>>>>>>>> couldn't find an available UDC
> >>>>>>>>> g_dnl_register: failed!, error: -19
> >>>>>>>>> exit not allowed from main input shell.
> >>>>>>>>>
> >>>>>>>>> Can you advise what bind/unbind command would be necessary here?  
> >>>>>>>>
> >>>>>>>> Either 'unbind usb_ether' or run 'dm tree' -> look up the path to usb_ether in the tree (it will be hanging under usb_peripheral or some such), and then use 'unbind <that path>'.  
> >>>>>>>
> >>>>>>> Nice `dm tree` command, never used it before.
> >>>>>>>
> >>>>>>> Even when I unbind usb_ether I still get the same error:  
> >>>>>>>      >>> => unbind /ocp/usb at 47400000/usb at 47401000  
> >>>>>>> => fastboot usb 0  
> >>>>>>> couldn't find an available UDC
> >>>>>>> g_dnl_register: failed!, error: -19
> >>>>>>> exit not allowed from main input shell.
> >>>>>>>
> >>>>>>> Is there a specific gadget driver which I should bind again manually?  
> >>>>>>
> >>>>>> Can you share the output of dm tree before/after unbind ?
> >>>>>>
> >>>>>> fastboot should auto-bind to the right thing.  
> >>>>>
> >>>>> Ok. Apparently it does not, but I don't have any clue why. If you want
> >>>>> me to check something else I will. Here is the output:
> >>>>>
> >>>>> U-Boot 2023.07-00806-g979e7443428 (Jul 31 2023 - 11:17:06 +0200)  
> >>>>
> >>>> [...]  
> >>>>   >>>>>     watchdog      0  [ + ]   omap3_wdt             |   |-- wdt at 44e35000  
> >>>>>     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
> >>>>>     ethernet      0  [ + ]   eth_cpsw              |   |-- ethernet at 4a100000
> >>>>>     bootdev       2  [   ]   eth_bootdev           |   |   `-- ethernet at 4a100000.bootdev
> >>>>>     simple_bus   67  [   ]   ti_sysc               |   |-- target-module at 53100000
> >>>>>     simple_bus   68  [   ]   ti_sysc               |   |-- target-module at 53500000
> >>>>>     simple_bus   69  [   ]   ti_sysc               |   `-- target-module at 56000000
> >>>>>     clk          62  [   ]   fixed_clock           |-- clk_mcasp0_fixed
> >>>>>     bootstd       0  [   ]   bootstd_drv           |-- bootstd
> >>>>>     bootmeth      0  [   ]   bootmeth_efi          |   |-- efi
> >>>>>     bootmeth      1  [   ]   bootmeth_extlinux     |   |-- extlinux
> >>>>>     bootmeth      2  [   ]   bootmeth_pxe          |   |-- pxe
> >>>>>     bootmeth      3  [   ]   vbe_simple            |   `-- vbe_simple
> >>>>>     timer         0  [ + ]   omap_timer            `-- timer at 0  
> >>>>> => unbind /ocp/usb at 47400000/usb at 47401000  
> >>>>
> >>>> The commit message of this patch contains the following example:
> >>>> unbind /soc/usb-otg at 49000000 usb_ether
> >>>> so in your case, try
> >>>> unbind /ocp/usb at 47400000/usb at 47401000 usb_ether  
> >>>
> >>> Does not work, unfortunately:  
> >>> => unbind /ocp/usb at 47400000/usb at 47401000 usb_ether  
> >>> Cannot find a device with path /ocp/usb at 47400000/usb at 47401000  
> >>> => unbind /ocp/usb at 47400000/usb at 47401000  
> >>
> >> Did this even work before , i.e. without this series, if you were to use USB ethernet first and then fastboot second (that sequence is important) ?  
> > 
> > Yes it did.
> >   
> >> Can you debug this ? Basically the problem that happens is that if you run:
> >> unbind /ocp/usb at 47400000/usb at 47401000
> >> this unbind ti-musb-peripheral usb at 47401000 instead of just unbinding
> >> usb_ether usb_ether  
> > 
> > True.
> >   
> >> Maybe just try
> >> unbind usb_ether  
> >   
> > => unbind usb_ether  
> > unbind - Unbind a device from a driver
> > 
> > Usage:
> > unbind <node path> [<driver>]
> > unbind <class> <index>
> > unbind <class> <index> <driver>
> >   
> >> or
> >> unbind usb_ether usb_ether  
> >   
> > => unbind usb_ether usb_ether  
> > usb_ether is not a valid uclass
> >   
> >> ti-musb-peripheral usb at 47401000 has to stay in the dm tree output after the unbind. Or maybe try
> >>
> >> bind /ocp/usb at 47400000/usb at 47401000 ti-musb-peripheral  
> > 
> > Indeed when we perform the unbind, ti-musb-peripheral is removed. Yes,
> > binding it again like you advise makes it come back.
> >   
> >> and then the fastboot thing  
> > 
> > Unfortunately after binding it again, so with the following dm tree
> > snippet:
> > 
> >   misc          0  [ + ]   ti-musb-wrapper       |   |-- usb at 47400000
> >   usb           0  [   ]   ti-musb-host          |   |   |-- usb at 47401800
> >   usb           0  [   ]   ti-musb-peripheral    |   |   `-- usb at 47401000
> > 
> > It still fails:
> >   
> > => fastboot usb 0  
> > couldn't find an available UDC
> > g_dnl_register: failed!, error: -19
> > exit not allowed from main input shell.
> > 
> > Without this series, this works:  
> > => unbind /ocp/usb at 47400000/usb at 47401000
> > => bind /ocp/usb at 47400000/usb at 47401000 ti-musb-peripheral
> > => fastboot usb 0  
> 
> OK, so fastboot did not work even without this series without obscure workarounds ?

I'm happy you call the unbind/bind sequence an "obscure workaround" ;-)

The command "fastboot usb 0" works without your series, before tftp
or after tftp, it does not matter, it used to work. Applying this
series makes it always fail.

I was just reporting that, before your series, calling unbind would
also remove ti-musb-peripheral, but calling bind again with the above
line makes the usb_ether gadget and fastboot work again. Whereas with
your series the unbind behaves identically but the bind command does not
"fix" fastboot (tftp works fine in v3).

> Can you try and debug this ?

The breakage is not part of the existing code base, it was introduced
by the series. Maybe you can try with any other board with USB
peripheral and see if the behavior is identical?

> Does 'fastboot usb 1' work with this series by any chance ?

When fastboot works, starting it "blocks" the CLI. When I unbind the
peripheral driver on USB 0, the fastboot command does not block any
more and yet does not print anything, it just returns "immediately"
without any log.

When I run 'fastboot usb 1' it acts like that as well, nothing happens,
without error. It acts identically before and after this series.

Thanks,
Miquèl


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