From mboxrd@z Thu Jan 1 00:00:00 1970 From: hdegoede@redhat.com (Hans de Goede) Date: Sun, 18 Sep 2016 18:50:17 +0200 Subject: [PATCH 1/2] phy-sun4i-usb: Add sun4i_usb_phy_force_session_end() function Message-ID: <20160918165018.24547-1-hdegoede@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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). The phy-sun4i-usb code already has code to force a session end for devices without Vbus control. This commit adds a sun4i_usb_phy_force_session_end() function exporting this functionality to the sunxi-musb glue, so that it can force a session end to fixup the stuck state after a babble error. Signed-off-by: Hans de Goede --- drivers/phy/phy-sun4i-usb.c | 11 +++++++++++ include/linux/phy/phy-sun4i-usb.h | 7 +++++++ 2 files changed, 18 insertions(+) diff --git a/drivers/phy/phy-sun4i-usb.c b/drivers/phy/phy-sun4i-usb.c index 43c0d98..06f4e11a 100644 --- a/drivers/phy/phy-sun4i-usb.c +++ b/drivers/phy/phy-sun4i-usb.c @@ -470,6 +470,17 @@ void sun4i_usb_phy_set_squelch_detect(struct phy *_phy, bool enabled) } EXPORT_SYMBOL_GPL(sun4i_usb_phy_set_squelch_detect); +void sun4i_usb_phy_force_session_end(struct phy *_phy) +{ + struct sun4i_usb_phy *phy = phy_get_drvdata(_phy); + struct sun4i_usb_phy_data *data = to_sun4i_usb_phy_data(phy); + + data->id_det = -1; + data->force_session_end = true; + queue_delayed_work(system_wq, &data->detect, 0); +} +EXPORT_SYMBOL_GPL(sun4i_usb_phy_force_session_end); + static const struct phy_ops sun4i_usb_phy_ops = { .init = sun4i_usb_phy_init, .exit = sun4i_usb_phy_exit, diff --git a/include/linux/phy/phy-sun4i-usb.h b/include/linux/phy/phy-sun4i-usb.h index 50aed92..3bb773f 100644 --- a/include/linux/phy/phy-sun4i-usb.h +++ b/include/linux/phy/phy-sun4i-usb.h @@ -23,4 +23,11 @@ */ void sun4i_usb_phy_set_squelch_detect(struct phy *phy, bool enabled); +/** + * sun4i_usb_force_session_end() - Force the current session to end + * by reporting VBus low for 200+ ms + * @phy: reference to a sun4i usb phy + */ +void sun4i_usb_phy_force_session_end(struct phy *phy); + #endif -- 2.9.3