This is a note to let you know that I've just added the patch titled

usb: typec: tcpm: Fix VDMs sometimes not being forwarded to alt-mode

to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 5571ea3117ca22849072adb58074fb5a2fd12c00 Mon Sep 17 00:00:00 2001

From: Hans de Goede hdegoede@redhat.com Date: Mon, 16 Aug 2021 17:46:32 +0200 Subject: usb: typec: tcpm: Fix VDMs sometimes not being forwarded to alt-mode drivers

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.

Fixes: a20dcf53ea98 ("usb: typec: tcpm: Respond Not_Supported if no snk_vdo") Cc: stable stable@vger.kernel.org Cc: Kyle Tso kyletso@google.com Acked-by: Heikki Krogerus heikki.krogerus@linux.intel.com Acked-by: Kyle Tso kyletso@google.com Signed-off-by: Hans de Goede hdegoede@redhat.com Link: https://lore.kernel.org/r/20210816154632.381968-1-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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]);