linux-kernel - [PATCH 5.8 174/177] usb: typec: intel_pmc_mux: Do not configure Altmode HPD High

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Date:   Tue, 15 Sep 2020 16:14:05 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Utkarsh Patel <utkarsh.h.patel@...el.com>,
        Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Subject: [PATCH 5.8 174/177] usb: typec: intel_pmc_mux: Do not configure Altmode HPD High

From: Utkarsh Patel <utkarsh.h.patel@...el.com>

commit 294955fd43dbf1e8f3a84cffa4797c6f22badc31 upstream.

According to the PMC Type C Subsystem (TCSS) Mux programming guide rev
0.7, bit 14 is reserved in Alternate mode.
In DP Alternate Mode state, if the HPD_STATE (bit 7) field in the
status update command VDO is set to HPD_HIGH, HPD is configured via
separate HPD mode request after configuring DP Alternate mode request.
Configuring reserved bit may show unexpected behaviour.
So do not configure them while issuing the Alternate Mode request.

Fixes: 7990be48ef4d ("usb: typec: mux: intel: Handle alt mode HPD_HIGH")
Cc: stable@...r.kernel.org
Signed-off-by: Utkarsh Patel <utkarsh.h.patel@...el.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
Link: https://lore.kernel.org/r/20200907142152.35678-2-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/usb/typec/mux/intel_pmc_mux.c |    4 ----
 1 file changed, 4 deletions(-)

--- a/drivers/usb/typec/mux/intel_pmc_mux.c
+++ b/drivers/usb/typec/mux/intel_pmc_mux.c
@@ -63,7 +63,6 @@ enum {
 #define PMC_USB_ALTMODE_DP_MODE_SHIFT	8
 
 /* TBT specific Mode Data bits */
-#define PMC_USB_ALTMODE_HPD_HIGH	BIT(14)
 #define PMC_USB_ALTMODE_TBT_TYPE	BIT(17)
 #define PMC_USB_ALTMODE_CABLE_TYPE	BIT(18)
 #define PMC_USB_ALTMODE_ACTIVE_LINK	BIT(20)
@@ -180,9 +179,6 @@ pmc_usb_mux_dp(struct pmc_usb_port *port
 	req.mode_data |= (state->mode - TYPEC_STATE_MODAL) <<
 			 PMC_USB_ALTMODE_DP_MODE_SHIFT;
 
-	if (data->status & DP_STATUS_HPD_STATE)
-		req.mode_data |= PMC_USB_ALTMODE_HPD_HIGH;
-
 	ret = pmc_usb_command(port, (void *)&req, sizeof(req));
 	if (ret)
 		return ret;