diff options
author | Sarah Sharp <[email protected]> | 2012-04-23 10:08:51 -0700 |
---|---|---|
committer | Sarah Sharp <[email protected]> | 2012-05-18 15:42:55 -0700 |
commit | e1f12eb6ba6f1e74007eb01ed26fad7c5239d62b (patch) | |
tree | 4c6753fc5091cd31b8cc0029e41f86f4f8c3b195 /drivers/usb/class | |
parent | e3567d2c15a7a8e2f992a5f7c7683453ca406d82 (diff) |
USB: Disable hub-initiated LPM for comms devices.
Hub-initiated LPM is not good for USB communications devices. Comms
devices should be able to tell when their link can go into a lower power
state, because they know when an incoming transmission is finished.
Ideally, these devices would slam their links into a lower power state,
using the device-initiated LPM, after finishing the last packet of their
data transfer.
If we enable the idle timeouts for the parent hubs to enable
hub-initiated LPM, we will get a lot of useless LPM packets on the bus
as the devices reject LPM transitions when they're in the middle of
receiving data. Worse, some devices might blindly accept the
hub-initiated LPM and power down their radios while they're in the
middle of receiving a transmission.
The Intel Windows folks are disabling hub-initiated LPM for all USB
communications devices under a xHCI USB 3.0 host. In order to keep
the Linux behavior as close as possible to Windows, we need to do the
same in Linux.
Set the disable_hub_initiated_lpm flag for for all USB communications
drivers. I know there aren't currently any USB 3.0 devices that
implement these class specifications, but we should be ready if they do.
Signed-off-by: Sarah Sharp <[email protected]>
Cc: Marcel Holtmann <[email protected]>
Cc: Gustavo Padovan <[email protected]>
Cc: Johan Hedberg <[email protected]>
Cc: Hansjoerg Lipp <[email protected]>
Cc: Tilman Schmidt <[email protected]>
Cc: Karsten Keil <[email protected]>
Cc: Peter Korsgaard <[email protected]>
Cc: Jan Dumon <[email protected]>
Cc: Petko Manolov <[email protected]>
Cc: Steve Glendinning <[email protected]>
Cc: "John W. Linville" <[email protected]>
Cc: Kalle Valo <[email protected]>
Cc: "Luis R. Rodriguez" <[email protected]>
Cc: Jouni Malinen <[email protected]>
Cc: Vasanthakumar Thiagarajan <[email protected]>
Cc: Senthil Balasubramanian <[email protected]>
Cc: Christian Lamparter <[email protected]>
Cc: Brett Rudley <[email protected]>
Cc: Roland Vossen <[email protected]>
Cc: Arend van Spriel <[email protected]>
Cc: "Franky (Zhenhui) Lin" <[email protected]>
Cc: Kan Yan <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Jussi Kivilinna <[email protected]>
Cc: Ivo van Doorn <[email protected]>
Cc: Gertjan van Wingerde <[email protected]>
Cc: Helmut Schaa <[email protected]>
Cc: Herton Ronaldo Krzesinski <[email protected]>
Cc: Hin-Tak Leung <[email protected]>
Cc: Larry Finger <[email protected]>
Cc: Chaoming Li <[email protected]>
Cc: Daniel Drake <[email protected]>
Cc: Ulrich Kunitz <[email protected]>
Signed-off-by: Sarah Sharp <[email protected]>
Diffstat (limited to 'drivers/usb/class')
-rw-r--r-- | drivers/usb/class/cdc-acm.c | 1 | ||||
-rw-r--r-- | drivers/usb/class/cdc-wdm.c | 1 |
2 files changed, 2 insertions, 0 deletions
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index b32ccb461019..f2a120eea9d4 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1664,6 +1664,7 @@ static struct usb_driver acm_driver = { #ifdef CONFIG_PM .supports_autosuspend = 1, #endif + .disable_hub_initiated_lpm = 1, }; /* diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 631bb952d0f6..ea8b304f0e85 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -1034,6 +1034,7 @@ static struct usb_driver wdm_driver = { .post_reset = wdm_post_reset, .id_table = wdm_ids, .supports_autosuspend = 1, + .disable_hub_initiated_lpm = 1, }; module_usb_driver(wdm_driver); |