Patch "usb: typec: tpcm: Fix PORT_RESET behavior for self powered devices" has been added to the 6.6-stable tree

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

    usb: typec: tpcm: Fix PORT_RESET behavior for self powered devices

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     usb-typec-tpcm-fix-port_reset-behavior-for-self-powered-devices.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From 197331b27ac890d0209232d5f669830cd00e8918 Mon Sep 17 00:00:00 2001
From: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
Date: Wed, 28 Feb 2024 00:05:12 +0000
Subject: usb: typec: tpcm: Fix PORT_RESET behavior for self powered devices

From: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>

commit 197331b27ac890d0209232d5f669830cd00e8918 upstream.

While commit 69f89168b310 ("usb: typec: tpcm: Fix issues with power being
removed during reset") fixes the boot issues for bus powered devices such
as LibreTech Renegade Elite/Firefly, it trades off the CC pins NOT being
Hi-Zed during errory recovery (i.e PORT_RESET) for devices which are NOT
bus powered(a.k.a self powered). This change Hi-Zs the CC pins only for
self powered devices, thus preventing brown out for bus powered devices

Adhering to spec is gaining more importance due to the Common charger
initiative enforced by the European Union.

Quoting from the spec:
    4.5.2.2.2.1 ErrorRecovery State Requirements
    The port shall not drive VBUS or VCONN, and shall present a
    high-impedance to ground (above zOPEN) on its CC1 and CC2 pins.

Hi-Zing the CC pins is the inteded behavior for PORT_RESET.
CC pins are set to default state after tErrorRecovery in
PORT_RESET_WAIT_OFF.

    4.5.2.2.2.2 Exiting From ErrorRecovery State
    A Sink shall transition to Unattached.SNK after tErrorRecovery.
    A Source shall transition to Unattached.SRC after tErrorRecovery.

Fixes: 69f89168b310 ("usb: typec: tpcm: Fix issues with power being removed during reset")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Badhri Jagan Sridharan <badhri@xxxxxxxxxx>
Tested-by: Mark Brown <broonie@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240228000512.746252-1-badhri@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/usb/typec/tcpm/tcpm.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4859,8 +4859,11 @@ static void run_state_machine(struct tcp
 		break;
 	case PORT_RESET:
 		tcpm_reset_port(port);
-		tcpm_set_cc(port, tcpm_default_state(port) == SNK_UNATTACHED ?
-			    TYPEC_CC_RD : tcpm_rp_cc(port));
+		if (port->self_powered)
+			tcpm_set_cc(port, TYPEC_CC_OPEN);
+		else
+			tcpm_set_cc(port, tcpm_default_state(port) == SNK_UNATTACHED ?
+				    TYPEC_CC_RD : tcpm_rp_cc(port));
 		tcpm_set_state(port, PORT_RESET_WAIT_OFF,
 			       PD_T_ERROR_RECOVERY);
 		break;


Patches currently in stable-queue which might be from badhri@xxxxxxxxxx are

queue-6.6/usb-typec-tpcm-fix-port_reset-behavior-for-self-powered-devices.patch




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