lkml.org 
[lkml]   [2019]   [Feb]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.14 106/205] usb: musb: dsps: fix otg state machine
Date
4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 6010abf2c2c0e382d7e8ee44bd11f343aae90cce ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/musb/musb_dsps.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
index dbb482b7e0ba..b7d460adaa61 100644
--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -242,8 +242,13 @@ 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_PORT_MODE_HOST) {
--
2.19.1


\
 
 \ /
  Last update: 2019-02-11 15:59    [W:0.568 / U:6.296 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site