Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 3.12 107/116] usb: musb: call musb_start() only once in OTG mode | Date | Tue, 26 Nov 2013 16:58:00 -0800 |
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3.12-stable review patch. If anyone has any objections, please let me know.
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
commit ae44df2e21b50f9fff28ac75c57e399c04df812c upstream.
In commit 001dd84 ("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: Daniel Mack <zonque@gmail.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/usb/musb/musb_virthub.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-)
--- a/drivers/usb/musb/musb_virthub.c +++ b/drivers/usb/musb/musb_virthub.c @@ -220,6 +220,23 @@ int musb_hub_status_data(struct usb_hcd 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, @@ -362,7 +379,7 @@ 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:
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