diff options
author | Dan Williams <dan.j.williams@intel.com> | 2014-05-20 21:08:12 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-27 19:35:09 -0400 |
commit | 9262c19d14c433a6a1ba25c3ff897cb89e412309 (patch) | |
tree | 50f83b859b251a3e842953e4fb9619a05ece02da /drivers/usb/core/hub.c | |
parent | 600856c231ccb0cbf8afcf09066a8ab2a93ab03d (diff) |
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) | |||
818 | int port1; | 818 | int port1; |
819 | unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2; | 819 | unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2; |
820 | unsigned delay; | 820 | unsigned delay; |
821 | u16 wHubCharacteristics = | ||
822 | le16_to_cpu(hub->descriptor->wHubCharacteristics); | ||
823 | 821 | ||
824 | /* Enable power on each port. Some hubs have reserved values | 822 | /* Enable power on each port. Some hubs have reserved values |
825 | * of LPSM (> 2) in their descriptors, even though they are | 823 | * 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) | |||
827 | * but only emulate it. In all cases, the ports won't work | 825 | * but only emulate it. In all cases, the ports won't work |
828 | * unless we send these messages to the hub. | 826 | * unless we send these messages to the hub. |
829 | */ | 827 | */ |
830 | if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2) | 828 | if (hub_is_port_power_switchable(hub)) |
831 | dev_dbg(hub->intfdev, "enabling power on all ports\n"); | 829 | dev_dbg(hub->intfdev, "enabling power on all ports\n"); |
832 | else | 830 | else |
833 | dev_dbg(hub->intfdev, "trying to enable port power on " | 831 | 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, | |||
4417 | struct usb_device *hdev = hub->hdev; | 4415 | struct usb_device *hdev = hub->hdev; |
4418 | struct device *hub_dev = hub->intfdev; | 4416 | struct device *hub_dev = hub->intfdev; |
4419 | struct usb_hcd *hcd = bus_to_hcd(hdev->bus); | 4417 | struct usb_hcd *hcd = bus_to_hcd(hdev->bus); |
4420 | unsigned wHubCharacteristics = | ||
4421 | le16_to_cpu(hub->descriptor->wHubCharacteristics); | ||
4422 | struct usb_device *udev; | 4418 | struct usb_device *udev; |
4423 | int status, i; | 4419 | int status, i; |
4424 | unsigned unit_load; | 4420 | unsigned unit_load; |
@@ -4503,7 +4499,7 @@ static void hub_port_connect_change(struct usb_hub *hub, int port1, | |||
4503 | test_bit(port1, hub->removed_bits)) { | 4499 | test_bit(port1, hub->removed_bits)) { |
4504 | 4500 | ||
4505 | /* maybe switch power back on (e.g. root hub was reset) */ | 4501 | /* maybe switch power back on (e.g. root hub was reset) */ |
4506 | if ((wHubCharacteristics & HUB_CHAR_LPSM) < 2 | 4502 | if (hub_is_port_power_switchable(hub) |
4507 | && !port_is_power_on(hub, portstatus)) | 4503 | && !port_is_power_on(hub, portstatus)) |
4508 | set_port_feature(hdev, port1, USB_PORT_FEAT_POWER); | 4504 | set_port_feature(hdev, port1, USB_PORT_FEAT_POWER); |
4509 | 4505 | ||