diff options
| author | Apelete Seketeli <apelete@seketeli.net> | 2013-12-20 00:42:27 +0400 |
|---|---|---|
| committer | Felipe Balbi <balbi@ti.com> | 2013-12-20 19:53:59 +0400 |
| commit | 23db9fd238d6ca5aa165900bf14fb42e3e2d0815 (patch) | |
| tree | c0686a0a6700f2ff05ef01bac28ad8e2c864e2bc /drivers/usb/musb/musb_gadget.c | |
| parent | 10434d273ccdcee8eab4f5e08497d65841bbf354 (diff) | |
| download | linux-23db9fd238d6ca5aa165900bf14fb42e3e2d0815.tar.xz | |
usb: musb: fix setting JZ4740 gadget periphal mode on reset
JZ4740 USB Device Controller is not OTG compatible and does not have
DEVCTL register in silicon.
During ethernet-over-usb transactions, on reset, musb driver tries to
read from DEVCTL and consequently sets device as host (A-Device)
instead of peripheral (B-Device), which makes it a composite device to
the USB gadget driver.
This induces a kernel panic during power down where the USB gadget
driver does a null pointer dereference when trying to access the
composite device configuration.
On reset, do not rely on DEVCTL value for setting gadget peripheral
mode. Use is_otg flag instead to set it to B-Device.
Signed-off-by: Apelete Seketeli <apelete@seketeli.net>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Diffstat (limited to 'drivers/usb/musb/musb_gadget.c')
| -rw-r--r-- | drivers/usb/musb/musb_gadget.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c index c410a7ff150b..d4aa779339f1 100644 --- a/drivers/usb/musb/musb_gadget.c +++ b/drivers/usb/musb/musb_gadget.c @@ -2119,7 +2119,15 @@ __acquires(musb->lock) /* Normal reset, as B-Device; * or else after HNP, as A-Device */ - if (devctl & MUSB_DEVCTL_BDEVICE) { + if (!musb->g.is_otg) { + /* USB device controllers that are not OTG compatible + * may not have DEVCTL register in silicon. + * In that case, do not rely on devctl for setting + * peripheral mode. + */ + musb->xceiv->state = OTG_STATE_B_PERIPHERAL; + musb->g.is_a_peripheral = 0; + } else if (devctl & MUSB_DEVCTL_BDEVICE) { musb->xceiv->state = OTG_STATE_B_PERIPHERAL; musb->g.is_a_peripheral = 0; } else { |