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phy_sun4i_usb: set_mode: Allow using set_mode to force end the current session

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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@redhat.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
This commit is contained in:
Hans de Goede 2016-09-23 16:40:56 +03:00 committed by Kishon Vijay Abraham I
parent e4d5973f9c
commit 5d04c88379
1 changed files with 10 additions and 4 deletions
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14
drivers/phy/phy-sun4i-usb.c
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@ -436,25 +436,31 @@ 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);
int 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", new_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);