linux-kernel - Re: [PATCH v1] usb: typec: tcpm: Ignore CC and vbus changes in PORT

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Date:   Tue, 14 Apr 2020 13:05:22 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
        Badhri Jagan Sridharan <badhri@...gle.com>
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-usb@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1] usb: typec: tcpm: Ignore CC and vbus changes in
 PORT_RESET change

On 4/14/20 5:04 AM, Heikki Krogerus wrote:
> On Thu, Apr 02, 2020 at 02:59:47PM -0700, Badhri Jagan Sridharan wrote:
>> After PORT_RESET, the port is set to the appropriate
>> default_state. Ignore processing CC changes here as this
>> could cause the port to be switched into sink states
>> by default.
>>
>> echo source > /sys/class/typec/port0/port_type
>>
>> Before:
>> [  154.528547] pending state change PORT_RESET -> PORT_RESET_WAIT_OFF @ 100 ms
>> [  154.528560] CC1: 0 -> 0, CC2: 3 -> 0 [state PORT_RESET, polarity 0, disconnected]
>> [  154.528564] state change PORT_RESET -> SNK_UNATTACHED
>>
>> After:
>> [  151.068814] pending state change PORT_RESET -> PORT_RESET_WAIT_OFF @ 100 ms [rev3 NONE_AMS]
>> [  151.072440] CC1: 3 -> 0, CC2: 0 -> 0 [state PORT_RESET, polarity 0, disconnected]
>> [  151.172117] state change PORT_RESET -> PORT_RESET_WAIT_OFF [delayed 100 ms]
>> [  151.172136] pending state change PORT_RESET_WAIT_OFF -> SRC_UNATTACHED @ 870 ms [rev3 NONE_AMS]
>> [  152.060106] state change PORT_RESET_WAIT_OFF -> SRC_UNATTACHED [delayed 870 ms]
>> [  152.060118] Start toggling
> 
> Guenter, can you take a look at this?
> 

Sorry, looks like I missed the original patch. Makes sense to me.

Reviewed-by: Guenter Roeck <linux@...ck-us.net>

>> Signed-off-by: Badhri Jagan Sridharan <badhri@...gle.com>
>> ---
>>  drivers/usb/typec/tcpm/tcpm.c | 26 ++++++++++++++++++++++++++
>>  1 file changed, 26 insertions(+)
>>
>> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
>> index de3576e6530ab2..82b19ebd7838e0 100644
>> --- a/drivers/usb/typec/tcpm/tcpm.c
>> +++ b/drivers/usb/typec/tcpm/tcpm.c
>> @@ -3794,6 +3794,14 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1,
>>  		 */
>>  		break;
>>  
>> +	case PORT_RESET:
>> +	case PORT_RESET_WAIT_OFF:
>> +		/*
>> +		 * State set back to default mode once the timer completes.
>> +		 * Ignore CC changes here.
>> +		 */
>> +		break;
>> +
>>  	default:
>>  		if (tcpm_port_is_disconnected(port))
>>  			tcpm_set_state(port, unattached_state(port), 0);
>> @@ -3855,6 +3863,15 @@ static void _tcpm_pd_vbus_on(struct tcpm_port *port)
>>  	case SRC_TRY_DEBOUNCE:
>>  		/* Do nothing, waiting for sink detection */
>>  		break;
>> +
>> +	case PORT_RESET:
>> +	case PORT_RESET_WAIT_OFF:
>> +		/*
>> +		 * State set back to default mode once the timer completes.
>> +		 * Ignore vbus changes here.
>> +		 */
>> +		break;
>> +
>>  	default:
>>  		break;
>>  	}
>> @@ -3908,10 +3925,19 @@ static void _tcpm_pd_vbus_off(struct tcpm_port *port)
>>  	case PORT_RESET_WAIT_OFF:
>>  		tcpm_set_state(port, tcpm_default_state(port), 0);
>>  		break;
>> +
>>  	case SRC_TRY_WAIT:
>>  	case SRC_TRY_DEBOUNCE:
>>  		/* Do nothing, waiting for sink detection */
>>  		break;
>> +
>> +	case PORT_RESET:
>> +		/*
>> +		 * State set back to default mode once the timer completes.
>> +		 * Ignore vbus changes here.
>> +		 */
>> +		break;
>> +
>>  	default:
>>  		if (port->pwr_role == TYPEC_SINK &&
>>  		    port->attached)
>> -- 
>> 2.26.0.292.g33ef6b2f38-goog
> 
> thanks,
>