diff options
| author | Dan Williams <dan.j.williams@intel.com> | 2014-05-20 18:08:57 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-27 16:38:53 -0700 |
| commit | 7ad3c47088f9faec463f5226e5e968a5c3b0e593 (patch) | |
| tree | c0712608896ada6eef80671212b3d766d823618f /drivers/usb/core/hub.c | |
| parent | d5c3834e4af3acc4d7fc52faba2711c666655632 (diff) | |
usb: block suspension of superspeed port while hispeed peer is active
ClearPortFeature(PORT_POWER) on a usb3 port places the port in either a
DSPORT.Powered-off-detect / DSPORT.Powered-off-reset loop, or the
DSPORT.Powered-off state. There is no way to ensure that RX
terminations will persist in this state, so it is possible a device will
degrade to its usb2 connection. Prevent this by blocking power-off of a
usb3 port while its usb2 peer is active, and powering on a usb3 port
before its usb2 peer.
By default the latency between peer power-on events is 0. In order for
the device to not see usb2 active while usb3 is still powering up inject
the hub recommended power_on_good delay. In support of satisfying the
power_on_good delay outside of hub_power_on() refactor the places where
the delay is consumed to call a new hub_power_on_good_delay() helper.
Finally, because this introduces several new checks for whether a port
is_superspeed, cache that disctinction at port creation so that we don't
need to keep looking up the parent hub device.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
[alan]: add a 'superspeed' flag to the port
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/core/hub.c')
| -rw-r--r-- | drivers/usb/core/hub.c | 22 |
1 files changed, 5 insertions, 17 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 31a492a4a881..e492bca74425 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -36,11 +36,6 @@ #define USB_VENDOR_GENESYS_LOGIC 0x05e3 #define HUB_QUIRK_CHECK_PORT_AUTOSUSPEND 0x01 -static inline int hub_is_superspeed(struct usb_device *hdev) -{ - return (hdev->descriptor.bDeviceProtocol == USB_HUB_PR_SS); -} - /* 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. */ @@ -822,14 +817,9 @@ int usb_hub_clear_tt_buffer(struct urb *urb) } EXPORT_SYMBOL_GPL(usb_hub_clear_tt_buffer); -/* If do_delay is false, return the number of milliseconds the caller - * needs to delay. - */ -static unsigned hub_power_on(struct usb_hub *hub, bool do_delay) +static void hub_power_on(struct usb_hub *hub, bool do_delay) { int port1; - unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2; - unsigned delay; /* Enable power on each port. Some hubs have reserved values * of LPSM (> 2) in their descriptors, even though they are @@ -848,12 +838,8 @@ static unsigned hub_power_on(struct usb_hub *hub, bool do_delay) else usb_clear_port_feature(hub->hdev, port1, USB_PORT_FEAT_POWER); - - /* Wait at least 100 msec for power to become stable */ - delay = max(pgood_delay, (unsigned) 100); if (do_delay) - msleep(delay); - return delay; + msleep(hub_power_on_good_delay(hub)); } static int hub_hub_status(struct usb_hub *hub, @@ -1057,7 +1043,9 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type) * for HUB_POST_RESET, but it's easier not to. */ if (type == HUB_INIT) { - delay = hub_power_on(hub, false); + unsigned delay = hub_power_on_good_delay(hub); + + hub_power_on(hub, false); INIT_DELAYED_WORK(&hub->init_work, hub_init_func2); queue_delayed_work(system_power_efficient_wq, &hub->init_work, |