usb: typec: tcpm: Refactor tcpm_handle_vdm_request

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.

Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20200724174702.61754-4-hdegoede@redhat.com
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 d65358a..51400cc 100644 (file)
--- 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)
@@ -1080,10 +1088,10 @@ 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;
@@ -1099,9 +1107,6 @@ 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]));
 
@@ -1127,8 +1132,7 @@ 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;
@@ -1182,23 +1186,15 @@ 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:
@@ -1209,11 +1205,8 @@ 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;
                }
@@ -1223,15 +1216,15 @@ 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;
@@ -1239,6 +1232,9 @@ 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) {
@@ -1253,7 +1249,31 @@ 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);