Re: [PATCH] usb: typec: tcpm/tcpci_maxim: fix non-contaminant CC handling

[Greg Kroah-Hartman]

On Fri, Jul 26, 2024 at 07:01:13AM +0100, André Draszik wrote:
> Hi,
> 
> On Wed, 2024-07-10 at 07:28 +0100, André Draszik wrote:
> > tcpci_maxim currently never triggers the TCPM state machine when CC
> > status has not changed due to a contaminant but due to a real
> > connection event, i.e. a genuine plug event, meaning the system will
> > stay idle and not notify any subscribers.
> > 
> > The reason is that the initial state of the port is 'toggling', which
> > causes _max_tcpci_irq() to only drive the contamination part of the
> > TCPM state machine (via tcpm_port_clean()).
> > 
> > What should happen instead is that if no contamination was detected,
> > the TCPM should be notified of the CC change in this case.
> > 
> > To fix this, we update ...is_contaminant() to also allow its caller to
> > determine if more CC processing is required and then call into the TCPM
> > as required.
> > 
> > While at it, add a kernel-doc for max_contaminant_is_contaminant().
> > 
> > Note: the code has an issue where I2C errors during contaminant
> > detection also cause the TCPM state machine to not be updated. This
> > commit doesn't change this behaviour and should be addressed by
> > follow-up commit(s).
> > 
> > Signed-off-by: André Draszik <andre.draszik@xxxxxxxxxx>
> > ---
> >  drivers/usb/typec/tcpm/maxim_contaminant.c |  7 +++++--
> >  drivers/usb/typec/tcpm/tcpci_maxim.h       | 15 ++++++++++++++-
> >  drivers/usb/typec/tcpm/tcpci_maxim_core.c  | 12 ++++++++----
> >  3 files changed, 27 insertions(+), 7 deletions(-)
> 
> Any comments on this patch?

It's the middle of the merge window, nothing we can do until -rc1 is
out...

thanks,

greg k-h