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| author | Mathias Nyman <mathias.nyman@linux.intel.com> | 2021-12-10 13:16:53 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-15 23:48:37 +0100 |
| commit | f59f93cd1d720809466c7fd5aa16a236156c672b (patch) | |
| tree | c0e0683784e88c81b295bd65cb09b5f929b547f4 | |
| parent | a1f79504ceb3ffcd2b777e5ac84c97a0948c2dbd (diff) | |
| download | linux-f59f93cd1d720809466c7fd5aa16a236156c672b.tar.gz linux-f59f93cd1d720809466c7fd5aa16a236156c672b.tar.bz2 linux-f59f93cd1d720809466c7fd5aa16a236156c672b.zip | |
usb: hub: avoid warm port reset during USB3 disconnect
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>
| -rw-r--r-- | drivers/usb/core/hub.c | 24 |
1 files changed, 19 insertions, 5 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 00070a8a6507..e907dfa0ca6d 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -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) |