From 4288b7df4ae6629a4fb14aca2c489da01d4d19c3 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Tue, 31 Mar 2009 12:35:09 -0700 Subject: [PATCH] musb: support disconnect after HNP roleswitch Adjust HNP state machines in MUSB driver so that they handle the case where the cable is disconnected. The A-side machine was very wrong (unrecoverable); the B-Side was much less so. - A_PERIPHERAL ... as usual, the non-observability of the ID pin through Mentor's registers makes trouble. We can't go directly to A_WAIT_VFALL to end the session and start the disconnect processing. We can however sense link suspending, go to A_WAIT_BCON, and from there use OTG timeouts to finally trigger that A_WAIT_VFALL transition. (Hoping that nobody reconnects quickly to that port and notices the wrong state.) - B_HOST ... actually clear the Host Request (HR) bit as the messages say, disconnect the peripheral from the root hub, and don't detour through a suspend state. (In some cases this would eventually have cleaned up.) Also adjust the A_SUSPEND transition to respect the A_AIDL_BDIS timeout, so if HNP doesn't trigger quickly enough the A_WAIT_VFALL transition happens as it should. Signed-off-by: David Brownell --- drivers/usb/musb/musb_core.c | 41 +++++++++++++++++++++++++++----------- drivers/usb/musb/musb_gadget.c | 2 + drivers/usb/musb/musb_virthub.c | 4 +++ 3 files changed, 35 insertions(+), 12 deletions(-) diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c index 9dc995a..5770ccb 100644 --- a/drivers/usb/musb/musb_core.c +++ b/drivers/usb/musb/musb_core.c @@ -304,9 +304,11 @@ void musb_otg_timer_func(unsigned long data) musb->xceiv->state = OTG_STATE_B_PERIPHERAL; musb->is_active = 0; break; + case OTG_STATE_A_SUSPEND: case OTG_STATE_A_WAIT_BCON: - DBG(1, "HNP: a_wait_bcon timeout; back to a_host\n"); - musb_hnp_stop(musb); + DBG(1, "HNP: %s timeout\n", otg_state_string(musb)); + musb_set_vbus(musb, 0); + musb->xceiv->state = OTG_STATE_A_WAIT_VFALL; break; default: DBG(1, "HNP: Unhandled mode %s\n", otg_state_string(musb)); @@ -324,15 +326,12 @@ void musb_hnp_stop(struct musb *musb) void __iomem *mbase = musb->mregs; u8 reg; + DBG(1, "HNP: stop from %s\n", otg_state_string(musb)); + switch (musb->xceiv->state) { case OTG_STATE_A_PERIPHERAL: - case OTG_STATE_A_WAIT_VFALL: - case OTG_STATE_A_WAIT_BCON: - DBG(1, "HNP: Switching back to A-host\n"); musb_g_disconnect(musb); - musb->xceiv->state = OTG_STATE_A_IDLE; - MUSB_HST_MODE(musb); - musb->is_active = 0; + DBG(1, "HNP: back to %s\n", otg_state_string(musb)); break; case OTG_STATE_B_HOST: DBG(1, "HNP: Disabling HR\n"); @@ -775,7 +774,16 @@ static irqreturn_t musb_stage2_irq(struct musb *musb, u8 int_usb, #endif /* HOST */ #ifdef CONFIG_USB_MUSB_OTG case OTG_STATE_B_HOST: - musb_hnp_stop(musb); + /* REVISIT this behaves for "real disconnect" + * cases; make sure the other transitions from + * from B_HOST act right too. The B_HOST code + * in hnp_stop() is currently not used... + */ + musb_root_disconnect(musb); + musb_to_hcd(musb)->self.is_b_host = 0; + musb->xceiv->state = OTG_STATE_B_PERIPHERAL; + MUSB_DEV_MODE(musb); + musb_g_disconnect(musb); break; case OTG_STATE_A_PERIPHERAL: musb_hnp_stop(musb); @@ -807,10 +815,19 @@ static irqreturn_t musb_stage2_irq(struct musb *musb, u8 int_usb, switch (musb->xceiv->state) { #ifdef CONFIG_USB_MUSB_OTG case OTG_STATE_A_PERIPHERAL: - /* - * We cannot stop HNP here, devctl BDEVICE might be - * still set. + /* We also come here if the cable is removed, since + * this silicon doesn't report ID-no-longer-grounded. + * + * We depend on T(a_wait_bcon) to shut us down, and + * hope users don't do anything dicey during this + * undesired detour through A_WAIT_BCON. */ + musb_hnp_stop(musb); + usb_hcd_resume_root_hub(musb_to_hcd(musb)); + musb_root_disconnect(musb); + musb_platform_try_idle(musb, jiffies + + msecs_to_jiffies(musb->a_wait_bcon + ? : OTG_TIME_A_WAIT_BCON)); break; #endif case OTG_STATE_B_PERIPHERAL: diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c index 7dd3d59..8b3c4e2 100644 --- a/drivers/usb/musb/musb_gadget.c +++ b/drivers/usb/musb/musb_gadget.c @@ -1962,9 +1962,11 @@ void musb_g_disconnect(struct musb *musb) DBG(2, "Unhandled disconnect %s, setting a_idle\n", otg_state_string(musb)); musb->xceiv->state = OTG_STATE_A_IDLE; + MUSB_HST_MODE(musb); break; case OTG_STATE_A_PERIPHERAL: musb->xceiv->state = OTG_STATE_A_WAIT_BCON; + MUSB_HST_MODE(musb); break; case OTG_STATE_B_WAIT_ACON: case OTG_STATE_B_HOST: diff --git a/drivers/usb/musb/musb_virthub.c b/drivers/usb/musb/musb_virthub.c index 14f7cf3..e8ef925 100644 --- a/drivers/usb/musb/musb_virthub.c +++ b/drivers/usb/musb/musb_virthub.c @@ -83,6 +83,10 @@ static void musb_port_suspend(struct musb *musb, bool do_suspend) musb->xceiv->state = OTG_STATE_A_SUSPEND; musb->is_active = is_otg_enabled(musb) && musb->xceiv->host->b_hnp_enable; + if (musb->is_active) + mod_timer(&musb->otg_timer, jiffies + + msecs_to_jiffies( + OTG_TIME_A_AIDL_BDIS)); musb_platform_try_idle(musb, 0); break; #ifdef CONFIG_USB_MUSB_OTG -- 1.6.0.4