diff options
| author | Dan Williams | 2014-05-21 03:08:12 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2014-05-28 01:35:09 +0200 |
| commit | 9262c19d14c433a6a1ba25c3ff897cb89e412309 (patch) | |
| tree | 50f83b859b251a3e842953e4fb9619a05ece02da /drivers/usb/core/hub.c | |
| parent | USB: mutual exclusion for resetting a hub and power-managing a port (diff) | |
| download | kernel-qcow2-linux-9262c19d14c433a6a1ba25c3ff897cb89e412309.tar.gz kernel-qcow2-linux-9262c19d14c433a6a1ba25c3ff897cb89e412309.tar.xz kernel-qcow2-linux-9262c19d14c433a6a1ba25c3ff897cb89e412309.zip | |
usb: disable port power control if not supported in wHubCharacteristics
A hub indicates whether it supports per-port power control via the
wHubCharacteristics field in its descriptor. If it is not supported
a hub will still emulate ClearPortPower(PORT_POWER) requests by
stopping the link state machine. However, since this does not save
power do not bother suspending.
This also consolidates support checks into a
hub_is_port_power_switchable() helper.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
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 | 8 |
1 files changed, 2 insertions, 6 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 5f43c22ba787..77b91888abef 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -818,8 +818,6 @@ static unsigned hub_power_on(struct usb_hub *hub, bool do_delay) int port1; unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2; unsigned delay; - u16 wHubCharacteristics = - le16_to_cpu(hub->descriptor->wHubCharacteristics); /* Enable power on each port. Some hubs have reserved values * of LPSM (> 2) in their descriptors, even though they are @@ -827,7 +825,7 @@ static unsigned hub_power_on(struct usb_hub *hub, bool do_delay) * but only emulate it. In all cases, the ports won't work * unless we send these messages to the hub. */ - if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2) + if (hub_is_port_power_switchable(hub)) dev_dbg(hub->intfdev, "enabling power on all ports\n"); else dev_dbg(hub->intfdev, "trying to enable port power on " @@ -4417,8 +4415,6 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1, struct usb_device *hdev = hub->hdev; struct device *hub_dev = hub->intfdev; struct usb_hcd *hcd = bus_to_hcd(hdev->bus); - unsigned wHubCharacteristics = - le16_to_cpu(hub->descriptor->wHubCharacteristics); struct usb_device *udev; int status, i; unsigned unit_load; @@ -4503,7 +4499,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1, test_bit(port1, hub->removed_bits)) { /* maybe switch power back on (e.g. root hub was reset) */ - if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2 + if (hub_is_port_power_switchable(hub) && !port_is_power_on(hub, portstatus)) set_port_feature(hdev, port1, USB_PORT_FEAT_POWER); |