The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f41bfc7e9c7c1d721c8752f1853cde43e606ad43 Mon Sep 17 00:00:00 2001
From: Kyle Tso kyletso@google.com Date: Tue, 1 Jun 2021 20:31:48 +0800 Subject: [PATCH] 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: 193a68011fdc ("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
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index 9ce8c9af4da5..a1bf0dc5babf 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -1547,19 +1547,25 @@ 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