Re: [PATCH 0/4] usb: typec: ucsi: Fix various locking issues

[Heikki Krogerus <heikki.krogerus@linux.intel.com>]

On Sun, Aug 09, 2020 at 04:19:00PM +0200, Hans de Goede wrote:
> Hi Heikki, et al.,
> 
> As discussed before here is my fix for the AB BA lock inversion issue
> which lockdep found in the ucsi code.
> 
> While working on the AB BA fix I added a
> WARN_ON(!mutex_is_locked(&ucsi->ppm_lock)) to ucsi_run_command() and
> that found me some more unrelated issues of ucsi_run_command() getting
> called without the ppm_lock held. This is fixed in the second patch.
> This made me realize that the ppm_lock handling should probably just
> be pushed down to inside ucsi_run_command() instead of letting the
> callers worry about this.
> 
> In essence the first 3 patches are all related and all boil down to
> push the ppm_lock handling down into ucsi_run_command(), removing the
> difference between ucsi_run_command() and ucsi_send_command(). I have
> been thinking that we may want to just squash these 3 together. I've
> left them as separate patches now as thet document how I go to the
> end result after the 3th patch and having them separate might be
> easier for reviewing purposes. Let me know if you want a v2 of this
> patchset with them squashed into a single "usb: typec: ucsi: Rework
> ppm_lock handling" commit (with the commit messages merged).
> 
> The 4th patch makes the also already discussed change of holding
> con->lock for the entire duration of ucsi_register_port().

I'm fine with having them in separate pathes like that. This all looks
good to me. Thanks for fixing this. For the whole series:

Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>


-- 
heikki