linux-kernel - Re: [PATCH v2] Revert "usb: typec: tcpm: fix cc role at port reset"

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Date: Thu, 18 Jan 2024 11:35:27 +0200
From: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
To: Badhri Jagan Sridharan <badhri@...gle.com>
Cc: gregkh@...uxfoundation.org, linux@...ck-us.net, kyletso@...gle.com,
	linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org,
	rdbabiera@...gle.com, amitsd@...gle.com, stable@...r.kernel.org,
	frank.wang@...k-chips.com,
	Gábor Stefanik <netrolller.3d@...il.com>
Subject: Re: [PATCH v2] Revert "usb: typec: tcpm: fix cc role at port reset"

Hi,

On Wed, Jan 17, 2024 at 11:47:42AM +0000, Badhri Jagan Sridharan wrote:
> This reverts commit 1e35f074399dece73d5df11847d4a0d7a6f49434.
> 
> Given that ERROR_RECOVERY calls into PORT_RESET for Hi-Zing
> the CC pins, setting CC pins to default state during PORT_RESET
> breaks error recovery.
> 
> 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.
> 
> Cc: stable@...r.kernel.org
> Cc: Frank Wang <frank.wang@...k-chips.com>
> Fixes: 1e35f074399d ("usb: typec: tcpm: fix cc role at port reset")
> Signed-off-by: Badhri Jagan Sridharan <badhri@...gle.com>
> ---
>  drivers/usb/typec/tcpm/tcpm.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 5945e3a2b0f7..9d410718eaf4 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -4876,8 +4876,7 @@ static void run_state_machine(struct tcpm_port *port)
>  		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));
> +		tcpm_set_cc(port, TYPEC_CC_OPEN);
>  		tcpm_set_state(port, PORT_RESET_WAIT_OFF,
>  			       PD_T_ERROR_RECOVERY);
>  		break;

Gábor had some concerns with this in v1.

thanks,

-- 
heikki