[PATCH 3.4 012/146] usb: common: otg-fsm: only signal connect after switching to peripheral

From: lizf
Date: Tue Sep 15 2015 - 05:56:03 EST


From: Peter Chen <peter.chen@xxxxxxxxxxxxx>

3.4.109-rc1 review patch. If anyone has any objections, please let me know.

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


commit 990919cad55a8c38fc73b0a6a0c9e5e4e927a5f8 upstream.

We should signal connect (pull up dp) after we have already
at peripheral mode, otherwise, the dp may be toggled due to
we reset controller or do disconnect during the initialization
for peripheral, then, the host may be confused during the
enumeration, eg, it finds the reset can't succeed, but the
device is still there, see below error message.

hub 1-0:1.0: USB hub found
hub 1-0:1.0: 1 port detected
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: Cannot enable port 1. Maybe the USB cable is bad?
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: Cannot enable port 1. Maybe the USB cable is bad?
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: Cannot enable port 1. Maybe the USB cable is bad?
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: cannot reset port 1 (err = -32)
hub 1-0:1.0: Cannot enable port 1. Maybe the USB cable is bad?
hub 1-0:1.0: unable to enumerate USB device on port 1

Fixes: the issue existed when the otg fsm code was added.
Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
[lizf: Backported to 3.4:
- adjust filename
- adjust context]
Signed-off-by: Zefan Li <lizefan@xxxxxxxxxx>
---
drivers/usb/otg/otg_fsm.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/otg/otg_fsm.c b/drivers/usb/otg/otg_fsm.c
index ade131a..e87edda 100644
--- a/drivers/usb/otg/otg_fsm.c
+++ b/drivers/usb/otg/otg_fsm.c
@@ -138,9 +138,9 @@ int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
break;
case OTG_STATE_B_PERIPHERAL:
otg_chrg_vbus(fsm, 0);
- otg_loc_conn(fsm, 1);
otg_loc_sof(fsm, 0);
otg_set_protocol(fsm, PROTO_GADGET);
+ otg_loc_conn(fsm, 1);
break;
case OTG_STATE_B_WAIT_ACON:
otg_chrg_vbus(fsm, 0);
@@ -200,10 +200,10 @@ int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)

break;
case OTG_STATE_A_PERIPHERAL:
- otg_loc_conn(fsm, 1);
otg_loc_sof(fsm, 0);
otg_set_protocol(fsm, PROTO_GADGET);
otg_drv_vbus(fsm, 1);
+ otg_loc_conn(fsm, 1);
break;
case OTG_STATE_A_WAIT_VFALL:
otg_drv_vbus(fsm, 0);
--
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/