Question on typec_unregister_altmode

Question on typec_unregister_altmode

[Shah, Nehal-bakulchandra]

Hi Heikki,

While working on one of the project i have observed one potential issue with typec_unregister_altmode.

If we unregister partners altmode then following code may fail and give the crash.


typec_mux_put(to_altmode(adev)->mux);

As partner does not get the mux during the register alt mode only port register alt mode has it.

so i think adev->mux should be checked for NULL/invalida pointer. Please correct my understanding.


Regards

Nehal

Re: Question on typec_unregister_altmode

[Heikki Krogerus]

Hi,

On Thu, Apr 15, 2021 at 04:19:06PM +0530, Shah, Nehal-bakulchandra wrote:
> Hi Heikki,
> 
> While working on one of the project i have observed one potential issue with typec_unregister_altmode.
> 
> If we unregister partners altmode then following code may fail and give the crash.

What crash?

> typec_mux_put(to_altmode(adev)->mux);
> 
> As partner does not get the mux during the register alt mode only port register alt mode has it.
> 
> so i think adev->mux should be checked for NULL/invalida pointer. Please correct my understanding.

If you check the implementation of typec_mux_put(), it already does
that. I don't understand the problem you are seeing?

If you are seeing a crash, then there should be a backtrace. Can you
please share that?

thanks,

-- 
heikki