At the moment the port over-current message is displayed only if the
over-current condition is permanent.
But in case of permanent short-circuit or over-current, some USB
power-distribution switches (such as the TPS20xx, etc.), after the
over-current detection and the consequent shutdown, return in the
normal state.
So, in these cases, the over-current error message never appears.
To overcome this problem, the "over-current condition" message is
displayed even after a series of some over-current events.
Signed-off-by: Flavio Suligoi <f.suligoi@xxxxxxx>
---
drivers/usb/core/hub.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 86658a81d284..24ef09ad208b 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -50,6 +50,9 @@
#define USB_TP_TRANSMISSION_DELAY_MAX 65535 /* ns */
#define USB_PING_RESPONSE_TIME 400 /* ns */
+#define USB_OC_COOL_DOWN_TIME 100 /* ms */
+#define USB_OC_REPEATED_MSG_DELAY 2000 /* ms */
+
/* Protect struct usb_device->state and ->children members
* Note: Both are also protected by ->dev.sem, except that ->state can
* change to USB_STATE_NOTATTACHED even when the semaphore isn't held. */
@@ -5565,6 +5568,11 @@ static void port_event(struct usb_hub *hub, int port1)
}
}
+ /*
+ * The over-current events can be continuous or intermittent (sometimes
+ * the event disappears after the cooling-down time); in both cases
+ * display an error message.
+ */
if (portchange & USB_PORT_STAT_C_OVERCURRENT) {
u16 status = 0, unused;
port_dev->over_current_count++;
@@ -5574,10 +5582,12 @@ static void port_event(struct usb_hub *hub, int port1)
port_dev->over_current_count);
usb_clear_port_feature(hdev, port1,
USB_PORT_FEAT_C_OVER_CURRENT);
- msleep(100); /* Cool down */
+ msleep(USB_OC_COOL_DOWN_TIME); /* Cool down */
hub_power_on(hub, true);
hub_port_status(hub, port1, &status, &unused);
- if (status & USB_PORT_STAT_OVERCURRENT)
+ if ((status & USB_PORT_STAT_OVERCURRENT) ||
+ !(port_dev->over_current_count %
+ (USB_OC_REPEATED_MSG_DELAY / USB_OC_COOL_DOWN_TIME)))
dev_err(&port_dev->dev, "over-current condition\n");
}
--
2.25.1
