Commit ae44df2e authored Oct 15, 2013 by Sebastian Andrzej Siewior Committed by Felipe Balbi Oct 17, 2013

usb: musb: call musb_start() only once in OTG mode



In commit 001dd84a ("usb: musb: start musb on the udc side, too") it was
ensured that the state engine is started also in OTG mode after a
removal / insertion of the gadget.
Unfortunately this change also introduced a bug: If the device is
configured as OTG and it connected with a remote host _without_ loading
a gadget then we bug() later (because musb->otg->gadget is not
initialized).
Initially I assumed it might be nice to have the host part of musb in
OTG mode working without having a gadget loaded. This bug and fact that
it wasn't working like this before the host/gadget split made me realize
that this was a silly idea.
This patch now introduces back the old behavior where in OTG mode the
host mode is only working after the gadget has been loaded.

Cc: stable@vger.kernel.org # v3.11
Cc: Daniel Mack <zonque@gmail.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

parent 811f3303

drivers/usb/musb/musb_virthub.c

+18 −1

Original line number	Diff line number	Diff line
		@@ -266,6 +266,23 @@ int musb_hub_status_data(struct usb_hcd hcd, char buf)
		return retval;
		}

		static int musb_has_gadget(struct musb *musb)
		{
		/*
		* In host-only mode we start a connection right away. In OTG mode
		* we have to wait until we loaded a gadget. We don't really need a
		* gadget if we operate as a host but we should not start a session
		* as a device without a gadget or else we explode.
		*/
		#ifdef CONFIG_USB_MUSB_HOST
		return 1;
		#else
		if (musb->port_mode == MUSB_PORT_MODE_HOST)
		return 1;
		return musb->g.dev.driver != NULL;
		#endif
		}

		int musb_hub_control(
		struct usb_hcd *hcd,
		u16 typeReq,
		@@ -408,7 +425,7 @@ int musb_hub_control(
		* initialization logic, e.g. for OTG, or change any
		* logic relating to VBUS power-up.
		*/
		if (!hcd->self.is_b_host)
		if (!hcd->self.is_b_host && musb_has_gadget(musb))
		musb_start(musb);
		break;
		case USB_PORT_FEAT_RESET: