On Fri, Jul 24, 2020 at 07:47:00PM +0200, Hans de Goede wrote:
> Refactor tcpm_handle_vdm_request and its tcpm_pd_svdm helper function so
> that reporting the results of the vdm to the altmode-driver is separated
> out into a clear separate step inside tcpm_handle_vdm_request, instead
> of being scattered over various places inside the tcpm_pd_svdm helper.
>
> This is a preparation patch for fixing an AB BA lock inversion between the
> tcpm code and some altmode drivers.
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> Changes in v2:
> - Keep "if (adev && pdev)" checks as is instead of modifying them
> ---
> drivers/usb/typec/tcpm/tcpm.c | 76 ++++++++++++++++++++++-------------
> 1 file changed, 48 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
> index ee239b54bcd8..03a0c083ee9a 100644
> --- a/drivers/usb/typec/tcpm/tcpm.c
> +++ b/drivers/usb/typec/tcpm/tcpm.c
> @@ -159,6 +159,14 @@ enum pd_msg_request {
> PD_MSG_DATA_SOURCE_CAP,
> };
>
> +enum adev_actions {
> + ADEV_NONE = 0,
> + ADEV_NOTIFY_USB_AND_QUEUE_VDM,
> + ADEV_QUEUE_VDM,
> + ADEV_QUEUE_VDM_SEND_EXIT_MODE_ON_FAIL,
> + ADEV_ATTENTION,
> +};
> +
> /* Events from low level driver */
>
> #define TCPM_CC_EVENT BIT(0)
> @@ -1078,10 +1086,10 @@ static void tcpm_register_partner_altmodes(struct tcpm_port *port)
>
> #define supports_modal(port) PD_IDH_MODAL_SUPP((port)->partner_ident.id_header)
>
> -static int tcpm_pd_svdm(struct tcpm_port *port, const u32 *p, int cnt,
> - u32 *response)
> +static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev,
> + const u32 *p, int cnt, u32 *response,
> + enum adev_actions *adev_action)
> {
> - struct typec_altmode *adev;
> struct typec_altmode *pdev;
> struct pd_mode_data *modep;
> int rlen = 0;
> @@ -1097,9 +1105,6 @@ static int tcpm_pd_svdm(struct tcpm_port *port, const u32 *p, int cnt,
>
> modep = &port->mode_data;
>
> - adev = typec_match_altmode(port->port_altmode, ALTMODE_DISCOVERY_MAX,
> - PD_VDO_VID(p[0]), PD_VDO_OPOS(p[0]));
> -
> pdev = typec_match_altmode(port->partner_altmode, ALTMODE_DISCOVERY_MAX,
> PD_VDO_VID(p[0]), PD_VDO_OPOS(p[0]));
>
> @@ -1125,8 +1130,7 @@ static int tcpm_pd_svdm(struct tcpm_port *port, const u32 *p, int cnt,
> break;
> case CMD_ATTENTION:
> /* Attention command does not have response */
> - if (adev)
> - typec_altmode_attention(adev, p[1]);
> + *adev_action = ADEV_ATTENTION;
> return 0;
> default:
> break;
> @@ -1180,23 +1184,15 @@ static int tcpm_pd_svdm(struct tcpm_port *port, const u32 *p, int cnt,
> case CMD_ENTER_MODE:
> if (adev && pdev) {
> typec_altmode_update_active(pdev, true);
> -
> - if (typec_altmode_vdm(adev, p[0], &p[1], cnt)) {
> - response[0] = VDO(adev->svid, 1,
> - CMD_EXIT_MODE);
> - response[0] |= VDO_OPOS(adev->mode);
> - return 1;
> - }
> + *adev_action = ADEV_QUEUE_VDM_SEND_EXIT_MODE_ON_FAIL;
> }
> return 0;
> case CMD_EXIT_MODE:
> if (adev && pdev) {
> typec_altmode_update_active(pdev, false);
> -
> /* Back to USB Operation */
> - WARN_ON(typec_altmode_notify(adev,
> - TYPEC_STATE_USB,
> - NULL));
> + *adev_action = ADEV_NOTIFY_USB_AND_QUEUE_VDM;
> + return 0;
> }
> break;
> default:
> @@ -1207,11 +1203,8 @@ static int tcpm_pd_svdm(struct tcpm_port *port, const u32 *p, int cnt,
> switch (cmd) {
> case CMD_ENTER_MODE:
> /* Back to USB Operation */
> - if (adev)
> - WARN_ON(typec_altmode_notify(adev,
> - TYPEC_STATE_USB,
> - NULL));
> - break;
> + *adev_action = ADEV_NOTIFY_USB_AND_QUEUE_VDM;
> + return 0;
> default:
> break;
> }
> @@ -1221,15 +1214,15 @@ static int tcpm_pd_svdm(struct tcpm_port *port, const u32 *p, int cnt,
> }
>
> /* Informing the alternate mode drivers about everything */
> - if (adev)
> - typec_altmode_vdm(adev, p[0], &p[1], cnt);
> -
> + *adev_action = ADEV_QUEUE_VDM;
> return rlen;
> }
>
> static void tcpm_handle_vdm_request(struct tcpm_port *port,
> const __le32 *payload, int cnt)
> {
> + enum adev_actions adev_action = ADEV_NONE;
> + struct typec_altmode *adev;
> u32 p[PD_MAX_PAYLOAD];
> u32 response[8] = { };
> int i, rlen = 0;
> @@ -1237,6 +1230,9 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port,
> for (i = 0; i < cnt; i++)
> p[i] = le32_to_cpu(payload[i]);
>
> + adev = typec_match_altmode(port->port_altmode, ALTMODE_DISCOVERY_MAX,
> + PD_VDO_VID(p[0]), PD_VDO_OPOS(p[0]));
> +
> if (port->vdm_state == VDM_STATE_BUSY) {
> /* If UFP responded busy retry after timeout */
> if (PD_VDO_CMDT(p[0]) == CMDT_RSP_BUSY) {
> @@ -1251,7 +1247,31 @@ static void tcpm_handle_vdm_request(struct tcpm_port *port,
> }
>
> if (PD_VDO_SVDM(p[0]))
> - rlen = tcpm_pd_svdm(port, p, cnt, response);
> + rlen = tcpm_pd_svdm(port, adev, p, cnt, response, &adev_action);
> +
> + if (adev) {
> + switch (adev_action) {
> + case ADEV_NONE:
> + break;
> + case ADEV_NOTIFY_USB_AND_QUEUE_VDM:
> + WARN_ON(typec_altmode_notify(adev, TYPEC_STATE_USB, NULL));
> + typec_altmode_vdm(adev, p[0], &p[1], cnt);
> + break;
> + case ADEV_QUEUE_VDM:
> + typec_altmode_vdm(adev, p[0], &p[1], cnt);
> + break;
> + case ADEV_QUEUE_VDM_SEND_EXIT_MODE_ON_FAIL:
> + if (typec_altmode_vdm(adev, p[0], &p[1], cnt)) {
> + response[0] = VDO(adev->svid, 1, CMD_EXIT_MODE);
> + response[0] |= VDO_OPOS(adev->mode);
> + rlen = 1;
> + }
> + break;
> + case ADEV_ATTENTION:
> + typec_altmode_attention(adev, p[1]);
> + break;
> + }
> + }
>
> if (rlen > 0)
> tcpm_queue_vdm(port, response[0], &response[1], rlen - 1);
> --
> 2.26.2
thanks,
--
heikki
