usb: typec: tpcm: Fix issues with power being removed during reset

commit 69f89168b310878be82d7d97bc0d22068ad858c0 upstream.

Since the merge of b717dfbf73e8 ("Revert "usb: typec: tcpm: fix
cc role at port reset"") into mainline the LibreTech Renegade
Elite/Firefly has died during boot, the main symptom observed in testing
is a sudden stop in console output.  Gábor Stefanik identified in review
that the patch would cause power to be removed from devices without
batteries (like this board), observing that while the patch is correct
according to the spec this appears to be an oversight in the spec.

Given that the change makes previously working systems unusable let's
revert it, there was some discussion of identifying systems that have
alternative power and implementing the standards conforming behaviour in
only that case.

Fixes: b717dfbf73e8 ("Revert "usb: typec: tcpm: fix cc role at port reset"")
Cc: stable <stable@kernel.org>
Cc: Badhri Jagan Sridharan <badhri@google.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20240212-usb-fix-renegade-v1-1-22c43c88d635@kernel.org
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 47ae2d520fda5fc946477ebc7f3e8a97df39d257..6d455ca76125e393f17191884c2410a49b717574 100644 (file)
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4862,7 +4862,8 @@ static void run_state_machine(struct tcpm_port *port)
                break;
        case PORT_RESET:
                tcpm_reset_port(port);
-               tcpm_set_cc(port, TYPEC_CC_OPEN);
+               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;