From: Mathias Nyman mathias.nyman@linux.intel.com
[ Upstream commit f59f93cd1d720809466c7fd5aa16a236156c672b ]
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... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Stable-dep-of: 2521106fc732 ("usb: hub: Don't try to recover devices lost during warm reset.") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/core/hub.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index f0739bc9e25ac..3aab5fa8f8e61 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2829,6 +2829,8 @@ 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 @@ -5653,6 +5655,7 @@ 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); @@ -5729,17 +5732,27 @@ 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); @@ -5747,6 +5760,7 @@ static void port_event(struct usb_hub *hub, int port1) usb_lock_port(port_dev); connect_change = 0; } + break; }
if (connect_change)