musb_hdrc: host vbus and connect/disconnect fixes

Teach host side VBUS powerup and connect logic about the problem whereby
the HDRC core wrongly reports VBUS_ERROR during initial powerup.

Remove previous non-working workaround for tusb powering VBUS:  don't
try handling CPEN by hand.

Rest of the fix for disconnection issues in A_SUSPEND.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

diff --git a/drivers/usb/musb/musbdefs.h b/drivers/usb/musb/musbdefs.h
index cea6ea7..ce3c77e 100644 (file)
--- a/drivers/usb/musb/musbdefs.h
+++ b/drivers/usb/musb/musbdefs.h
@@ -415,6 +415,7 @@ struct musb {
        struct musb_hw_ep        aLocalEnd[MUSB_C_NUM_EPS];
 #define control_ep             aLocalEnd
 
+#define VBUSERR_RETRY_COUNT    3
        u16                     vbuserr_retry;
        u16 wEndMask;
        u8 bEndCount;

diff --git a/drivers/usb/musb/plat_uds.c b/drivers/usb/musb/plat_uds.c
index dd471d0..b345d6f 100644 (file)
--- a/drivers/usb/musb/plat_uds.c
+++ b/drivers/usb/musb/plat_uds.c
@@ -108,9 +108,6 @@
 #endif
 
 #include "musbdefs.h"
-// #ifdef CONFIG_USB_MUSB_HDRC_HCD
-#define VBUSERR_RETRY_COUNT    2               /* is this too few? */
-// #endif
 
 
 #ifdef CONFIG_ARCH_DAVINCI
@@ -411,8 +408,52 @@ static irqreturn_t musb_stage0_irq(struct musb * pThis, u8 bIntrUSB,
        }
 
        if (bIntrUSB & MGC_M_INTR_VBUSERROR) {
+               int     ignore = 0;
+
+               /* During connection as an A-Device, we may see a short
+                * current spikes causing voltage drop, because of cable
+                * and peripheral capacitance combined with vbus draw.
+                * (So: less common with truly self-powered devices, where
+                * vbus doesn't act like a power supply.)
+                *
+                * Such spikes are short; usually less than ~500 usec, max
+                * of ~2 msec.  That is, they're not sustained overcurrent
+                * errors, though they're reported using VBUSERROR irqs.
+                *
+                * Workarounds:  (a) hardware: use self powered devices.
+                * (b) software:  ignore non-repeated VBUS errors.
+                *
+                * REVISIT:  do delays from lots of DEBUG_KERNEL checks
+                * make trouble here, keeping VBUS < 4.4V ?
+                */
+               switch (pThis->xceiv.state) {
+               case OTG_STATE_A_HOST:
+                       /* recovery is dicey once we've gotten past the
+                        * initial stages of enumeration, but if VBUS
+                        * stayed ok at the other end of the link, and
+                        * another reset is due (at least for high speed,
+                        * to redo the chirp etc), it might work OK...
+                        */
+               case OTG_STATE_A_WAIT_BCON:
+               case OTG_STATE_A_WAIT_VRISE:
+                       if (pThis->vbuserr_retry) {
+                               pThis->vbuserr_retry--;
+                               ignore = 1;
+                               devctl |= MGC_M_DEVCTL_SESSION;
+                               musb_writeb(pBase, MGC_O_HDRC_DEVCTL, devctl);
+                       } else {
+                               pThis->port1_status |=
+                                         (1 << USB_PORT_FEAT_OVER_CURRENT)
+                                       | (1 << USB_PORT_FEAT_C_OVER_CURRENT);
+                       }
+                       break;
+               default:
+                       break;
+               }
 
-               DBG(1, "VBUS_ERROR (%02x, %s), retry #%d\n", devctl,
+               DBG(1, "VBUS_ERROR in %s (%02x, %s), retry #%d, port1 %08x\n",
+                               otg_state_string(pThis),
+                               devctl,
                                ({ char *s;
                                switch (devctl & MGC_M_DEVCTL_VBUS) {
                                case 0 << MGC_S_DEVCTL_VBUS:
@@ -425,13 +466,14 @@ static irqreturn_t musb_stage0_irq(struct musb * pThis, u8 bIntrUSB,
                                default:
                                        s = "VALID"; break;
                                }; s; }),
-                               pThis->vbuserr_retry);
+                               VBUSERR_RETRY_COUNT - pThis->vbuserr_retry,
+                               pThis->port1_status);
 
                /* go through A_WAIT_VFALL then start a new session */
-               musb_set_vbus(pThis, 0);
+               if (!ignore)
+                       musb_set_vbus(pThis, 0);
                handled = IRQ_HANDLED;
-       } else
-               pThis->vbuserr_retry = VBUSERR_RETRY_COUNT;
+       }
 
        if (bIntrUSB & MGC_M_INTR_CONNECT) {
                handled = IRQ_HANDLED;
@@ -468,10 +510,13 @@ static irqreturn_t musb_stage0_irq(struct musb * pThis, u8 bIntrUSB,
                        pThis->xceiv.state = OTG_STATE_B_HOST;
                        break;
                default:
-                       pThis->xceiv.state = OTG_STATE_A_HOST;
+                       if ((devctl & MGC_M_DEVCTL_VBUS)
+                                       == (3 << MGC_S_DEVCTL_VBUS))
+                               pThis->xceiv.state = OTG_STATE_A_HOST;
                        break;
                }
-               DBG(1, "CONNECT (%s)\n", otg_state_string(pThis));
+               DBG(1, "CONNECT (%s) devctl %02x\n",
+                               otg_state_string(pThis), devctl);
        }
 #endif /* CONFIG_USB_MUSB_HDRC_HCD */
 
@@ -566,18 +611,35 @@ static irqreturn_t musb_stage2_irq(struct musb * pThis, u8 bIntrUSB,
 #endif
 
        if ((bIntrUSB & MGC_M_INTR_DISCONNECT) && !pThis->bIgnoreDisconnect) {
-               DBG(1, "DISCONNECT as %s, devctl %02x\n",
+               DBG(1, "DISCONNECT (%s) as %s, devctl %02x\n",
+                               otg_state_string(pThis),
                                MUSB_MODE(pThis), devctl);
                handled = IRQ_HANDLED;
-               pThis->is_active = 0;
 
-               /* need to check it against pThis, because devctl is going
-                * to report ID low as soon as the device gets disconnected
-                */
-               if (is_host_active(pThis))
+               switch (pThis->xceiv.state) {
+#ifdef CONFIG_USB_MUSB_HDRC_HCD
+               case OTG_STATE_A_HOST:
+               case OTG_STATE_A_SUSPEND:
                        musb_root_disconnect(pThis);
-               else
+                       break;
+#endif /* HOST */
+#ifdef CONFIG_USB_MUSB_OTG
+               case OTG_STATE_A_PERIPHERAL:
+               case OTG_STATE_B_HOST:
+                       musb_root_disconnect(pThis);
+                       /* FALLTHROUGH */
+               case OTG_STATE_B_WAIT_ACON:
+#endif /* OTG */
+#ifdef CONFIG_USB_GADGET_MUSB_HDRC
+               case OTG_STATE_B_PERIPHERAL:
                        musb_g_disconnect(pThis);
+                       break;
+#endif /* GADGET */
+               default:
+                       WARN("unhandled DISCONNECT transition (%s)\n",
+                               otg_state_string(pThis));
+                       break;
+               }
 
                schedule_work(&pThis->irq_work);
        }
@@ -1299,8 +1361,6 @@ irqreturn_t musb_interrupt(struct musb *musb)
        if (musb->int_usb & STAGE0_MASK)
                retval |= musb_stage0_irq(musb, musb->int_usb,
                                devctl, power);
-       else
-               musb->vbuserr_retry = VBUSERR_RETRY_COUNT;
 
        /* "stage 1" is handling endpoint irqs */
 
@@ -1450,7 +1510,7 @@ musb_cable_show(struct device *dev, struct device_attribute *attr, char *buf)
        int vbus;
 
        spin_lock_irqsave(&musb->Lock, flags);
-#ifdef CONFIG_USB_TUSB6010
+#if defined(CONFIG_USB_TUSB6010) && !defined(CONFIG_USB_MUSB_OTG)
        /* REVISIT: connect-A != connect-B ... */
        vbus = musb_platform_get_vbus_status(musb);
        if (vbus)

diff --cc drivers/usb/musb/tusb6010.c
Simple merge

diff --cc drivers/usb/musb/virthub.c
Simple merge