FROMGIT: usb: typec: tcpm: Correct the responses in SVDM Version 2.0 DFP

In USB PD Spec Rev 3.1 Ver 1.0, section "6.12.5 Applicability of
Structured VDM Commands", DFP is allowed and recommended to respond to
Discovery Identity with ACK. And in section "6.4.4.2.5.1 Commands other
than Attention", NAK should be returned only when receiving Messages
with invalid fields, Messages in wrong situation, or unrecognize
Messages.

Still keep the original design for SVDM Version 1.0 for backward
compatibilities.

Fixes: 193a68011f ("staging: typec: tcpm: Respond to Discover Identity commands")
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Kyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210601123151.3441914-2-kyletso@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit f41bfc7e9c
 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-next)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: If1dd588040c1a3d403d29f0436f9ab23c740ea20
This commit is contained in:
Kyle Tso 2021-06-01 20:31:48 +08:00 committed by Greg Kroah-Hartman
commit bbdac2c2ad

View file

@ -1597,19 +1597,25 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
if (PD_VDO_VID(p[0]) != USB_SID_PD)
break;
if (PD_VDO_SVDM_VER(p[0]) < svdm_version)
if (PD_VDO_SVDM_VER(p[0]) < svdm_version) {
typec_partner_set_svdm_version(port->partner,
PD_VDO_SVDM_VER(p[0]));
svdm_version = PD_VDO_SVDM_VER(p[0]);
}
tcpm_ams_start(port, DISCOVER_IDENTITY);
/* 6.4.4.3.1: Only respond as UFP (device) */
if (port->data_role == TYPEC_DEVICE &&
/*
* PD2.0 Spec 6.10.3: respond with NAK as DFP (data host)
* PD3.1 Spec 6.4.4.2.5.1: respond with NAK if "invalid field" or
* "wrong configuation" or "Unrecognized"
*/
if ((port->data_role == TYPEC_DEVICE || svdm_version >= SVDM_VER_2_0) &&
port->nr_snk_vdo) {
/*
* Product Type DFP and Connector Type are not defined in SVDM
* version 1.0 and shall be set to zero.
*/
if (typec_get_negotiated_svdm_version(typec) < SVDM_VER_2_0)
if (svdm_version < SVDM_VER_2_0)
response[1] = port->snk_vdo[0] & ~IDH_DFP_MASK
& ~IDH_CONN_MASK;
else