diff options
| author | Bin Liu <b-liu@ti.com> | 2018-12-18 16:58:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-18 17:46:31 +0300 |
| commit | 6010abf2c2c0e382d7e8ee44bd11f343aae90cce (patch) | |
| tree | 368377270dc06ddbe5c54fe48913957c6f03119d | |
| parent | 1d6e81a288e28d8d0e38e0501a324216f79bba35 (diff) | |
| download | linux-6010abf2c2c0e382d7e8ee44bd11f343aae90cce.tar.xz | |
usb: musb: dsps: fix otg state machine
Due to lack of ID pin interrupt event on AM335x devices, the musb dsps
driver uses polling to detect usb device attach for dual-role port.
But in the case if a micro-A cable adapter is attached without a USB device
attached to the cable, the musb state machine gets stuck in a_wait_vrise
state waiting for the MUSB_CONNECT interrupt which won't happen due to the
usb device is not attached. The state is stuck in a_wait_vrise even after
the micro-A cable is detached, which could cause VBUS retention if then the
dual-role port is attached to a host port.
To fix the problem, make a_wait_vrise as a transient state, then move the
state to either a_wait_bcon for host port or a_idle state for dual-role
port, if no usb device is attached to the port.
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/musb/musb_dsps.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c index 23a0df79ef21..1e6d78b1334e 100644 --- a/drivers/usb/musb/musb_dsps.c +++ b/drivers/usb/musb/musb_dsps.c @@ -227,8 +227,13 @@ static int dsps_check_status(struct musb *musb, void *unused) switch (musb->xceiv->otg->state) { case OTG_STATE_A_WAIT_VRISE: - dsps_mod_timer_optional(glue); - break; + if (musb->port_mode == MUSB_HOST) { + musb->xceiv->otg->state = OTG_STATE_A_WAIT_BCON; + dsps_mod_timer_optional(glue); + break; + } + /* fall through */ + case OTG_STATE_A_WAIT_BCON: /* keep VBUS on for host-only mode */ if (musb->port_mode == MUSB_HOST) { |