On Tue, Dec 3, 2024 at 1:51 PM Heikki Krogerus
<heikki.krogerus@xxxxxxxxxxxxxxx> wrote:
>
> On Tue, Dec 03, 2024 at 02:48:59PM +0200, Heikki Krogerus wrote:
> > On Tue, Dec 03, 2024 at 10:23:18AM +0000, Łukasz Bartosik wrote:
> > > OPM PPM LPM
> > > | 1.send cmd | |
> > > |-------------------------->| |
> > > | |-- |
> > > | | | 2.set busy bit in CCI |
> > > | |<- |
> > > | 3.notify the OPM | |
> > > |<--------------------------| |
> > > | | 4.send cmd to be executed |
> > > | |-------------------------->|
> > > | | |
> > > | | 5.cmd completed |
> > > | |<--------------------------|
> > > | | |
> > > | |-- |
> > > | | | 6.set cmd completed |
> > > | |<- bit in CCI |
> > > | | |
> > > | 7.notify the OPM | |
> > > |<--------------------------| |
> > > | | |
> > > | 8.handle notification | |
> > > | from point 3, read CCI | |
> > > |<--------------------------| |
> > > | | |
> > >
> > > When the PPM receives command from the OPM (p.1) it sets the busy bit
> > > in the CCI (p.2), sends notification to the OPM (p.3) and forwards the
> > > command to be executed by the LPM (p.4). When the PPM receives command
> > > completion from the LPM (p.5) it sets command completion bit in the CCI
> > > (p.6) and sends notification to the OPM (p.7). If command execution by
> > > the LPM is fast enough then when the OPM starts handling the notification
> > > from p.3 in p.8 and reads the CCI value it will see command completion bit
> > > set and will call complete(). Then complete() might be called again when
> > > the OPM handles notification from p.7.
> > >
> > > This fix replaces test_bit() with test_and_clear_bit()
> > > in ucsi_notify_common() in order to call complete() only
> > > once per request.
> > >
> > > This fix also reinitializes completion variable in
> > > ucsi_sync_control_common() before a command is sent.
> > >
> > > Fixes: 584e8df58942 ("usb: typec: ucsi: extract common code for command handling")
> > > Cc: stable@xxxxxxxxxxxxxxx
> > > Signed-off-by: Łukasz Bartosik <ukaszb@xxxxxxxxxxxx>
> >
> > Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx
>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
>
> Sorry about that typo.
>
> --
> heikki
Heikki, Dmitry,
Thank you for the review.
Regards,
Łukasz
