Re: [PATCH v3 2/2] usb: typec: tcpm: Fix wrong handling for Not_Supported in VDM AMS

[Guenter Roeck]

On Fri, May 07, 2021 at 02:23:00PM +0800, Kyle Tso wrote:
> Not_Supported Message is acceptable in VDM AMS. Redirect the VDM state
> machine to VDM_STATE_DONE when receiving Not_Supported and finish the
> VDM AMS.
> 
> Also, after the loop in vdm_state_machine_work, add more conditions of
> VDM states to clear the vdm_sm_running flag because those are all
> stopping states when leaving the loop.
> 
> In addition, finish the VDM AMS if the port partner responds BUSY.
> 
> Fixes: 8dea75e11380 ("usb: typec: tcpm: Protocol Error handling")
> Fixes: 8d3a0578ad1a ("usb: typec: tcpm: Respond Wait if VDM state machine is running")
> Signed-off-by: Kyle Tso <kyletso@xxxxxxxxxx>

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

> ---
> Changes since v2:
> - no changes
> 
>  drivers/usb/typec/tcpm/tcpm.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index 07a449f0e8fa..bf97db232f09 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -1897,7 +1897,6 @@ static void vdm_run_state_machine(struct tcpm_port *port)
>  
>  			if (res < 0) {
>  				port->vdm_state = VDM_STATE_ERR_BUSY;
> -				port->vdm_sm_running = false;
>  				return;
>  			}
>  		}
> @@ -1913,6 +1912,7 @@ static void vdm_run_state_machine(struct tcpm_port *port)
>  		port->vdo_data[0] = port->vdo_retry;
>  		port->vdo_count = 1;
>  		port->vdm_state = VDM_STATE_READY;
> +		tcpm_ams_finish(port);
>  		break;
>  	case VDM_STATE_BUSY:
>  		port->vdm_state = VDM_STATE_ERR_TMOUT;
> @@ -1978,7 +1978,7 @@ static void vdm_state_machine_work(struct kthread_work *work)
>  		 port->vdm_state != VDM_STATE_BUSY &&
>  		 port->vdm_state != VDM_STATE_SEND_MESSAGE);
>  
> -	if (port->vdm_state == VDM_STATE_ERR_TMOUT)
> +	if (port->vdm_state < VDM_STATE_READY)
>  		port->vdm_sm_running = false;
>  
>  	mutex_unlock(&port->lock);
> @@ -2569,6 +2569,16 @@ static void tcpm_pd_ctrl_request(struct tcpm_port *port,
>  			port->sink_cap_done = true;
>  			tcpm_set_state(port, ready_state(port), 0);
>  			break;
> +		case SRC_READY:
> +		case SNK_READY:
> +			if (port->vdm_state > VDM_STATE_READY) {
> +				port->vdm_state = VDM_STATE_DONE;
> +				if (tcpm_vdm_ams(port))
> +					tcpm_ams_finish(port);
> +				mod_vdm_delayed_work(port, 0);
> +				break;
> +			}
> +			fallthrough;
>  		default:
>  			tcpm_pd_handle_state(port,
>  					     port->pwr_role == TYPEC_SOURCE ?
> -- 
> 2.31.1.527.g47e6f16901-goog
>