A USB 3.0 device can transition to the Inactive state if a U1 or U2 exit
transition fails. The current code in hub_events simply issues a warm
reset, but does not call any pre-reset or post-reset driver methods (or
unbind/rebind drivers without them). Therefore the drivers won't know
their device has just been reset.
hub_events should instead call usb_reset_device. This means
hub_port_reset now needs to figure out whether it should issue a warm
reset or a hot reset. Because the code to decrement the
ehci_cf_port_reset_rwsem relies on the "warm" value, we can no longer
depend on that value if a hot reset is changing to a warm reset.
Instead, only down/up the sempaphore if the hub isn't a SuperSpeed hub.
When we warm reset a port with a connected device, make sure to notify
the xHC and USB core that the device was reset in hub_port_finish_reset.
The current code may recursively call hub_port_reset if a hot reset
failed. We can't leave that in while notifying the USB core and xHC of
the reset because it would cause hub_port_wait_reset to call
usb_set_device_state() twice, possibly disconnecting on a failed hot
reset, and reconnecting on a successful warm reset.
Rip out the recursive call. Instead, add code to hub_port_reset to
issue a warm reset if the hot reset fails, and try multiple warm resets
before giving up on the port. Make sure that hub_port_wait_reset sets
udev->speed on a warm reset, since a failed hot reset may cause a warm
reset to be tried.
Make sure all paths of hub_port_wait_reset and hub_port_finish_reset can
handle being called with a NULL udev. This will happen if hub_events
finds a previously-empty port in SS.Inactive or Compliance Mode.
Unconditionally clear the connect status change (CSC) bit for USB 3.0
hubs when the port reset is done. If we had to issue multiple warm
resets for a device, that bit may have been set if the device went into
SS.Inactive and then was successfully warm reset. In that case, we
return a successful status to caller, who may not clear the CSC bit.
This is bad for xHCI roothubs, since their port change events are
edge-triggered, not level-triggered. It's harmless to clear the CSC bit
on a failed port reset, since all the callers will now disable the port
on failure.
Finally, remove the FIXME note about needing disconnect() for a
NOTATTACHED device. This patch fixes that.
Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
---
drivers/usb/core/hub.c | 187 +++++++++++++++++++++++++-----------------------
1 files changed, 97 insertions(+), 90 deletions(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index fd04147..1215de5 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2539,77 +2539,39 @@ static int hub_port_wait_reset(struct usb_hub *hub, int port1,
(portstatus & USB_PORT_STAT_RESET))
goto delay;
- /*
- * Some buggy devices require a warm reset to be issued even
- * when the port appears not to be connected.
- */
- if (!warm) {
- /*
- * Some buggy devices can cause an NEC host controller
- * to transition to the "Error" state after a hot port
- * reset. This will show up as the port state in
- * "Inactive", and the port may also report a
- * disconnect. Forcing a warm port reset seems to make
- * the device work.
- *
- * See https://bugzilla.kernel.org/show_bug.cgi?id=41752
- */
- if (hub_port_warm_reset_required(hub, portstatus)) {
- int ret;
-
- if ((portchange & USB_PORT_STAT_C_CONNECTION))
- clear_port_feature(hub->hdev, port1,
- USB_PORT_FEAT_C_CONNECTION);
- if (portchange & USB_PORT_STAT_C_LINK_STATE)
- clear_port_feature(hub->hdev, port1,
- USB_PORT_FEAT_C_PORT_LINK_STATE);
- if (portchange & USB_PORT_STAT_C_RESET)
- clear_port_feature(hub->hdev, port1,
- USB_PORT_FEAT_C_RESET);
- dev_dbg(hub->intfdev, "hot reset failed, warm reset port %d\n",
- port1);
- ret = hub_port_reset(hub, port1,
- udev, HUB_BH_RESET_TIME,
- true);
- if ((portchange & USB_PORT_STAT_C_CONNECTION))
- clear_port_feature(hub->hdev, port1,
- USB_PORT_FEAT_C_CONNECTION);
- return ret;
- }
- /* Device went away? */
- if (!(portstatus & USB_PORT_STAT_CONNECTION))
- return -ENOTCONN;
+ if (hub_port_warm_reset_required(hub, portstatus))
+ return -ENOTCONN;
- /* bomb out completely if the connection bounced */
- if ((portchange & USB_PORT_STAT_C_CONNECTION))
- return -ENOTCONN;
+ /* Device went away? */
+ if (!(portstatus & USB_PORT_STAT_CONNECTION))
+ return -ENOTCONN;
- /* if we`ve finished resetting, then break out of
- * the loop
- */
- if (!(portstatus & USB_PORT_STAT_RESET) &&
- (portstatus & USB_PORT_STAT_ENABLE)) {
- if (hub_is_wusb(hub))
- udev->speed = USB_SPEED_WIRELESS;
- else if (hub_is_superspeed(hub->hdev))
- udev->speed = USB_SPEED_SUPER;
- else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
- udev->speed = USB_SPEED_HIGH;
- else if (portstatus & USB_PORT_STAT_LOW_SPEED)
- udev->speed = USB_SPEED_LOW;
- else
- udev->speed = USB_SPEED_FULL;
- return 0;
- }
- } else {
- if (!(portchange & USB_PORT_STAT_C_BH_RESET))
- goto delay;
+ /* bomb out completely if the connection bounced. A USB 3.0
+ * connection may bounce if multiple warm resets were issued,
+ * but the device may have successfully re-connected. Ignore it.
+ */
+ if (!hub_is_superspeed(hub->hdev) &&
+ (portchange & USB_PORT_STAT_C_CONNECTION))
+ return -ENOTCONN;
- if (!(portstatus & USB_PORT_STAT_CONNECTION) ||
- hub_port_warm_reset_required(hub,
- portstatus))
- return -ENOTCONN;
+ /* if we've finished resetting, then break out of
+ * the loop
+ */
+ if (!(portstatus & USB_PORT_STAT_RESET) &&
+ (portstatus & USB_PORT_STAT_ENABLE)) {
+ if (!udev)
+ return 0;
+ if (hub_is_wusb(hub))
+ udev->speed = USB_SPEED_WIRELESS;
+ else if (hub_is_superspeed(hub->hdev))
+ udev->speed = USB_SPEED_SUPER;
+ else if (portstatus & USB_PORT_STAT_HIGH_SPEED)
+ udev->speed = USB_SPEED_HIGH;
+ else if (portstatus & USB_PORT_STAT_LOW_SPEED)
+ udev->speed = USB_SPEED_LOW;
+ else
+ udev->speed = USB_SPEED_FULL;
return 0;
}
@@ -2627,16 +2589,16 @@ delay:
}
static void hub_port_finish_reset(struct usb_hub *hub, int port1,
- struct usb_device *udev, int *status, bool warm)
+ struct usb_device *udev, int *status)
{
switch (*status) {
case 0:
- if (!warm) {
- struct usb_hcd *hcd;
- /* TRSTRCY = 10 ms; plus some extra */
- msleep(10 + 40);
+ /* TRSTRCY = 10 ms; plus some extra */
+ msleep(10 + 40);
+ if (udev) {
+ struct usb_hcd *hcd = bus_to_hcd(udev->bus);
+
update_devnum(udev, 0);
- hcd = bus_to_hcd(udev->bus);
/* The xHC may think the device is already reset,
* so ignore the status.
*/
@@ -2648,14 +2610,15 @@ static void hub_port_finish_reset(struct usb_hub *hub, int port1,
case -ENODEV:
clear_port_feature(hub->hdev,
port1, USB_PORT_FEAT_C_RESET);
- /* FIXME need disconnect() for NOTATTACHED device */
if (hub_is_superspeed(hub->hdev)) {
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_BH_PORT_RESET);
clear_port_feature(hub->hdev, port1,
USB_PORT_FEAT_C_PORT_LINK_STATE);
+ clear_port_feature(hub->hdev, port1,
+ USB_PORT_FEAT_C_CONNECTION);
}
- if (!warm)
+ if (udev)
usb_set_device_state(udev, *status
? USB_STATE_NOTATTACHED
: USB_STATE_DEFAULT);
@@ -2668,18 +2631,30 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
struct usb_device *udev, unsigned int delay, bool warm)
{
int i, status;
+ u16 portchange, portstatus;
- if (!warm) {
- /* Block EHCI CF initialization during the port reset.
- * Some companion controllers don't like it when they mix.
- */
- down_read(&ehci_cf_port_reset_rwsem);
- } else {
- if (!hub_is_superspeed(hub->hdev)) {
+ if (!hub_is_superspeed(hub->hdev)) {
+ if (warm) {
dev_err(hub->intfdev, "only USB3 hub support "
"warm reset\n");
return -EINVAL;
}
+ /* Block EHCI CF initialization during the port reset.
+ * Some companion controllers don't like it when they mix.
+ */
+ down_read(&ehci_cf_port_reset_rwsem);
+ } else if (!warm) {
+ /*
+ * If the caller hasn't explicitly requested a warm reset,
+ * double check and see if one is needed.
+ */
+ status = hub_port_status(hub, port1,
+ &portstatus, &portchange);
+ if (status < 0)
+ goto done;
+
+ if (hub_port_warm_reset_required(hub, portstatus))
+ warm = true;
}
/* Reset the port */
@@ -2700,10 +2675,33 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
status);
}
- /* return on disconnect or reset */
+ /* Check for disconnect or reset */
if (status == 0 || status == -ENOTCONN || status == -ENODEV) {
- hub_port_finish_reset(hub, port1, udev, &status, warm);
- goto done;
+ hub_port_finish_reset(hub, port1, udev, &status);
+
+ if (!hub_is_superspeed(hub->hdev))
+ goto done;
+
+ /*
+ * If a USB 3.0 device migrates from reset to an error
+ * state, re-issue the warm reset.
+ */
+ if (hub_port_status(hub, port1,
+ &portstatus, &portchange) < 0)
+ goto done;
+
+ if (!hub_port_warm_reset_required(hub, portstatus))
+ goto done;
+
+ /*
+ * If the port is in SS.Inactive or Compliance Mode, the
+ * hot or warm reset failed. Try another warm reset.
+ */
+ if (!warm) {
+ dev_dbg(hub->intfdev, "hot reset failed, warm reset port %d\n",
+ port1);
+ warm = true;
+ }
}
dev_dbg (hub->intfdev,
@@ -2717,7 +2715,7 @@ static int hub_port_reset(struct usb_hub *hub, int port1,
port1);
done:
- if (!warm)
+ if (!hub_is_superspeed(hub->hdev))
up_read(&ehci_cf_port_reset_rwsem);
return status;
@@ -4708,12 +4706,21 @@ static void hub_events(void)
*/
if (hub_port_warm_reset_required(hub, portstatus)) {
int status;
+ struct usb_device *udev =
+ hub->ports[i - 1]->child;
dev_dbg(hub_dev, "warm reset port %d\n", i);
- status = hub_port_reset(hub, i, NULL,
- HUB_BH_RESET_TIME, true);
- if (status < 0)
- hub_port_disable(hub, i, 1);
+ if (!udev) {
+ status = hub_port_reset(hub, i,
+ NULL, HUB_BH_RESET_TIME,
+ true);
+ if (status < 0)
+ hub_port_disable(hub, i, 1);
+ } else {
+ usb_lock_device(udev);
+ status = usb_reset_device(udev);
+ usb_unlock_device(udev);
+ }
connect_change = 0;
}
--
1.7.9
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