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* [PATCH 1/2] phy-sun4i-usb: Add sun4i_usb_phy_force_session_end() function
@ 2016-09-18 16:50 Hans de Goede
  2016-09-18 16:50 ` [PATCH 2/2] musb: sunxi: Force session end on babble errors in host-mode Hans de Goede
  2016-09-20  4:45 ` [PATCH 1/2] phy-sun4i-usb: Add sun4i_usb_phy_force_session_end() function Kishon Vijay Abraham I
  0 siblings, 2 replies; 8+ messages in thread
From: Hans de Goede @ 2016-09-18 16:50 UTC (permalink / raw)
  To: linux-arm-kernel

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 <hdegoede@redhat.com>
---
 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

^ permalink raw reply related	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2016-09-22  8:05 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-09-18 16:50 [PATCH 1/2] phy-sun4i-usb: Add sun4i_usb_phy_force_session_end() function Hans de Goede
2016-09-18 16:50 ` [PATCH 2/2] musb: sunxi: Force session end on babble errors in host-mode Hans de Goede
2016-09-22  2:33   ` Bin Liu
2016-09-22  8:05     ` Hans de Goede
2016-09-20  4:45 ` [PATCH 1/2] phy-sun4i-usb: Add sun4i_usb_phy_force_session_end() function Kishon Vijay Abraham I
2016-09-21  8:05   ` Hans de Goede
2016-09-22  2:28     ` Bin Liu
2016-09-22  7:31       ` Hans de Goede

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