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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2013-10-15 18:29:22 +0200 |
|---|---|---|
| committer | Felipe Balbi <balbi@ti.com> | 2013-10-17 09:55:03 -0500 |
| commit | ae44df2e21b50f9fff28ac75c57e399c04df812c (patch) | |
| tree | d87431c6159128a25ef4f405b597d4eeafb1841e /drivers/usb | |
| parent | 811f33033f9e6a00756e38990d82214c8c619f4c (diff) | |
| download | linux-ae44df2e21b50f9fff28ac75c57e399c04df812c.tar.gz linux-ae44df2e21b50f9fff28ac75c57e399c04df812c.tar.bz2 linux-ae44df2e21b50f9fff28ac75c57e399c04df812c.zip | |
usb: musb: call musb_start() only once in OTG mode
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: 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>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/musb/musb_virthub.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/drivers/usb/musb/musb_virthub.c b/drivers/usb/musb/musb_virthub.c index a523950c2b32..d8bbdb366beb 100644 --- a/drivers/usb/musb/musb_virthub.c +++ b/drivers/usb/musb/musb_virthub.c @@ -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: |