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usb: hub: avoid warm port reset during USB3 disconnect

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During disconnect USB-3 ports often go via SS.Inactive link error state
before the missing terminations are noticed, and link finally goes to
RxDetect state

Avoid immediately warm-resetting ports in SS.Inactive state.
Let ports settle for a while and re-read the link status a few times 20ms
apart to see if the ports transitions out of SS.Inactive.

According to USB 3.x spec 7.5.2, a port in SS.Inactive should
automatically check for missing far-end receiver termination every
12 ms (SSInactiveQuietTimeout)

The futile multiple warm reset retries of a disconnected device takes
a lot of time, also the resetting of a removed devices has caused cases
where the reset bit got stuck for a long time on xHCI roothub.
This lead to issues in detecting new devices connected to the same port
shortly after.

Tested-by: Mark Pearson <markpearson@lenovo.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20211210111653.1378381-1-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Nyman 2021-12-10 13:16:53 +02:00 committed by Greg Kroah-Hartman
parent a1f79504ce
commit f59f93cd1d
1 changed files with 19 additions and 5 deletions
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24
drivers/usb/core/hub.c
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@ -2777,6 +2777,8 @@ static unsigned hub_is_wusb(struct usb_hub *hub)
#define PORT_INIT_TRIES 4
#endif /* CONFIG_USB_FEW_INIT_RETRIES */
#define DETECT_DISCONNECT_TRIES 5
#define HUB_ROOT_RESET_TIME 60 /* times are in msec */
#define HUB_SHORT_RESET_TIME 10
#define HUB_BH_RESET_TIME 50
@ -5543,6 +5545,7 @@ static void port_event(struct usb_hub *hub, int port1)
struct usb_device *udev = port_dev->child;
struct usb_device *hdev = hub->hdev;
u16 portstatus, portchange;
int i = 0;
connect_change = test_bit(port1, hub->change_bits);
clear_bit(port1, hub->event_bits);
@ -5619,17 +5622,27 @@ static void port_event(struct usb_hub *hub, int port1)
connect_change = 1;
/*
* Warm reset a USB3 protocol port if it's in
* SS.Inactive state.
* Avoid trying to recover a USB3 SS.Inactive port with a warm reset if
* the device was disconnected. A 12ms disconnect detect timer in
* SS.Inactive state transitions the port to RxDetect automatically.
* SS.Inactive link error state is common during device disconnect.
*/
if (hub_port_warm_reset_required(hub, port1, portstatus)) {
dev_dbg(&port_dev->dev, "do warm reset\n");
if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION)
while (hub_port_warm_reset_required(hub, port1, portstatus)) {
if ((i++ < DETECT_DISCONNECT_TRIES) && udev) {
u16 unused;
msleep(20);
hub_port_status(hub, port1, &portstatus, &unused);
dev_dbg(&port_dev->dev, "Wait for inactive link disconnect detect\n");
continue;
} else if (!udev || !(portstatus & USB_PORT_STAT_CONNECTION)
|| udev->state == USB_STATE_NOTATTACHED) {
dev_dbg(&port_dev->dev, "do warm reset, port only\n");
if (hub_port_reset(hub, port1, NULL,
HUB_BH_RESET_TIME, true) < 0)
hub_port_disable(hub, port1, 1);
} else {
dev_dbg(&port_dev->dev, "do warm reset, full device\n");
usb_unlock_port(port_dev);
usb_lock_device(udev);
usb_reset_device(udev);
@ -5637,6 +5650,7 @@ static void port_event(struct usb_hub *hub, int port1)
usb_lock_port(port_dev);
connect_change = 0;
}
break;
}
if (connect_change)