The sunxi musb has a bug where sometimes it will generate a babble
error on device disconnect instead of a disconnect irq. When this
happens the musb-controller switches from host mode to device mode
(it clears MUSB_DEVCTL_SESSION and sets MUSB_DEVCTL_BDEVICE) and
gets stuck in this state.
Clearing this requires reporting Vbus low for 200 or more ms, but
on some devices Vbus is simply always high (host-only mode, no Vbus
control).
This commit modifies sun4i_usb_phy_set_mode so that it will force
end the current session when called with the current mode, before this
commit calling set_mode with the current mode was a nop since id_det
would stay the same resulting in the detect_work not doing anything.
This allows the sunxi-musb glue to use sun4i_usb_phy_set_mode to force
end the current session without changing the mode, to fixup the stuck
state after a babble error.
Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
---
Changes in v2:
-New patch in v2 of this series replacing the
"phy-sun4i-usb: Add sun4i_usb_phy_force_session_end() function"
from v1
---
drivers/phy/phy-sun4i-usb.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/phy/phy-sun4i-usb.c b/drivers/phy/phy-sun4i-usb.c
index 43c0d98..d76538c 100644
--- a/drivers/phy/phy-sun4i-usb.c
+++ b/drivers/phy/phy-sun4i-usb.c
@@ -437,25 +437,32 @@ static int sun4i_usb_phy_set_mode(struct phy *_phy, enum phy_mode mode)
{
struct sun4i_usb_phy *phy = phy_get_drvdata(_phy);
struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy);
+ enum usb_dr_mode new_mode;
if (phy->index != 0)
return -EINVAL;
switch (mode) {
case PHY_MODE_USB_HOST:
- data->dr_mode = USB_DR_MODE_HOST;
+ new_mode = USB_DR_MODE_HOST;
break;
case PHY_MODE_USB_DEVICE:
- data->dr_mode = USB_DR_MODE_PERIPHERAL;
+ new_mode = USB_DR_MODE_PERIPHERAL;
break;
case PHY_MODE_USB_OTG:
- data->dr_mode = USB_DR_MODE_OTG;
+ new_mode = USB_DR_MODE_OTG;
break;
default:
return -EINVAL;
}
- dev_info(&_phy->dev, "Changing dr_mode to %d\n", (int)data->dr_mode);
+ if (new_mode != data->dr_mode) {
+ dev_info(&_phy->dev, "Changing dr_mode to %d\n",
+ (int)data->dr_mode);
+ data->dr_mode = new_mode;
+ }
+
+ data->id_det = -1; /* Force reprocessing of id */
data->force_session_end = true;
queue_delayed_work(system_wq, &data->detect, 0);
--
2.9.3
--
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