Prevent spurious connection events after resume by caching the current

plug state and comparing it with the current plug state when we receive
in interrupt.  Only call the connect/disconnect callbacks registered for
the port if the state really changed.  This prevents an spurious
attach/detach/attach sequence when resuming with a USB device connected.

ok patrick@

diff --git a/sys/dev/fdt/tipd.c b/sys/dev/fdt/tipd.c
index a1c7147..5d5ad2e 100644 (file)
--- a/sys/dev/fdt/tipd.c
+++ b/sys/dev/fdt/tipd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: tipd.c,v 1.2 2023/07/17 17:50:22 kettenis Exp $       */
+/*     $OpenBSD: tipd.c,v 1.3 2023/07/23 11:42:44 kettenis Exp $       */
 /*
  * Copyright (c) 2022 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -42,6 +42,7 @@
 #define TPS_SYSTEM_POWER_STATE 0x20
 #define  TPS_SYSTEM_POWER_STATE_S0     0
 #define  TPS_SYSTEM_POWER_STATE_S5     5
+#define TPS_POWER_STATUS       0x3f
 
 #define TPS_CMD(s)     ((s[3] << 24) | (s[2] << 16) | (s[1] << 8) | s[0])
 
@@ -59,6 +60,7 @@ struct tipd_softc {
        void                    *sc_ih;
 
        struct device_ports     sc_ports;
+       uint32_t                sc_status;
 };
 
 int    tipd_match(struct device *, void *, void *);
@@ -110,6 +112,7 @@ tipd_attach(struct device *parent, struct device *self, void *aux)
 
        printf("\n");
 
+       tipd_read_4(sc, TPS_STATUS, &sc->sc_status);
        tipd_write_8(sc, TPS_INT_MASK_1, CD_INT_PLUG_EVENT);
 
        node = OF_getnodebyname(node, "connector");
@@ -127,6 +130,9 @@ tipd_activate(struct device *self, int act)
        int error;
 
        switch (act) {
+       case DVACT_QUIESCE:
+               tipd_write_8(sc, TPS_INT_MASK_1, 0);
+               break;
        case DVACT_SUSPEND:
                state = TPS_SYSTEM_POWER_STATE_S5;
                error = tipd_exec(sc, "SSPS", &state, sizeof(state), NULL, 0);
@@ -139,6 +145,10 @@ tipd_activate(struct device *self, int act)
                if (error)
                        printf("%s: powerup failed\n", sc->sc_dev.dv_xname);
                break;
+       case DVACT_WAKEUP:
+               tipd_read_4(sc, TPS_STATUS, &sc->sc_status);
+               tipd_write_8(sc, TPS_INT_MASK_1, CD_INT_PLUG_EVENT);
+               break;
        }
 
        return 0;
@@ -197,11 +207,19 @@ tipd_intr(void *arg)
                error = tipd_read_4(sc, TPS_STATUS, &status);
                if (error)
                        goto fail;
-                       
-               if (status & TPS_STATUS_PLUG_PRESENT)
-                       tipd_connect(sc);
-               else
-                       tipd_disconnect(sc);
+
+               /*
+                * We may get a spurious plug event upon resume.  Make
+                * sure we only signal a new connection when the plug
+                * present state really changed.
+                */
+               if ((status ^ sc->sc_status) & TPS_STATUS_PLUG_PRESENT) {
+                       if (status & TPS_STATUS_PLUG_PRESENT)
+                               tipd_connect(sc);
+                       else
+                               tipd_disconnect(sc);
+                       sc->sc_status = status;
+               }
        }
 
 fail: