On Tue, Aug 17, 2021 at 6:07 PM Heikki Krogerus
<heikki.krogerus@xxxxxxxxxxxxxxx> wrote:
>
> On Mon, Aug 16, 2021 at 05:46:32PM +0200, Hans de Goede wrote:
> > Commit a20dcf53ea98 ("usb: typec: tcpm: Respond Not_Supported if no
> > snk_vdo"), stops tcpm_pd_data_request() calling tcpm_handle_vdm_request()
> > when port->nr_snk_vdo is not set. But the VDM might be intended for an
> > altmode-driver, in which case nr_snk_vdo does not matter.
> >
> > This change breaks the forwarding of connector hotplug (HPD) events
> > for displayport altmode on devices which don't set nr_snk_vdo.
> >
> > tcpm_pd_data_request() is the only caller of tcpm_handle_vdm_request(),
> > so we can move the nr_snk_vdo check to inside it, at which point we
> > have already looked up the altmode device so we can check for this too.
> >
> > Doing this check here also ensures that vdm_state gets set to
> > VDM_STATE_DONE if it was VDM_STATE_BUSY, even if we end up with
> > responding with PD_MSG_CTRL_NOT_SUPP later.
> >
> > Note that tcpm_handle_vdm_request() was already sending
> > PD_MSG_CTRL_NOT_SUPP in some circumstances, after moving the nr_snk_vdo
> > check the same error-path is now taken when that check fails. So that
> > we have only one error-path for this and not two. Replace the
> > tcpm_queue_message(PD_MSG_CTRL_NOT_SUPP) used by the existing error-path
> > with the more robust tcpm_pd_handle_msg() from the (now removed) second
> > error-path.
Thanks for fixing this problem!
> >
> > Cc: Kyle Tso <kyletso@xxxxxxxxxx>
> > Fixes: a20dcf53ea98 ("usb: typec: tcpm: Respond Not_Supported if no snk_vdo")
> > Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
>
> Acked-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
>
Acked-by: Kyle Tso <kyletso@xxxxxxxxxx>
> > ---
> > drivers/usb/typec/tcpm/tcpm.c | 13 +++++++------
> > 1 file changed, 7 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> > index b9bb63d749ec..f4079b5cb26d 100644
> > --- a/drivers/usb/typec/tcpm/tcpm.c
> > +++ b/drivers/usb/typec/tcpm/tcpm.c
> > @@ -1737,6 +1737,10 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
> > return rlen;
> > }
> >
> > +static void tcpm_pd_handle_msg(struct tcpm_port *port,
> > + enum pd_msg_request message,
> > + enum tcpm_ams ams);
> > +
> > static void tcpm_handle_vdm_request(struct tcpm_port *port,
> > const __le32 *payload, int cnt)
> > {
> > @@ -1764,11 +1768,11 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port,
> > port->vdm_state = VDM_STATE_DONE;
> > }
> >
> > - if (PD_VDO_SVDM(p[0])) {
> > + if (PD_VDO_SVDM(p[0]) && (adev || tcpm_vdm_ams(port) || port->nr_snk_vdo)) {
> > rlen = tcpm_pd_svdm(port, adev, p, cnt, response, &adev_action);
> > } else {
> > if (port->negotiated_rev >= PD_REV30)
> > - tcpm_queue_message(port, PD_MSG_CTRL_NOT_SUPP);
> > + tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
> > }
> >
> > /*
> > @@ -2471,10 +2475,7 @@ static void tcpm_pd_data_request(struct tcpm_port *port,
> > NONE_AMS);
> > break;
> > case PD_DATA_VENDOR_DEF:
> > - if (tcpm_vdm_ams(port) || port->nr_snk_vdo)
> > - tcpm_handle_vdm_request(port, msg->payload, cnt);
> > - else if (port->negotiated_rev > PD_REV20)
> > - tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
> > + tcpm_handle_vdm_request(port, msg->payload, cnt);
> > break;
> > case PD_DATA_BIST:
> > port->bist_request = le32_to_cpu(msg->payload[0]);
> > --
> > 2.31.1
>
> --
> heikki
