diff options
| author | Vincent Palatin <vpalatin@chromium.org> | 2011-12-05 19:33:51 +0000 |
|---|---|---|
| committer | Gerrit <chrome-bot@google.com> | 2011-12-06 14:01:26 -0800 |
| commit | 7b8b3434f8123e5dfb8494ed3908017c14804018 (patch) | |
| tree | 72199ac0a16e307b64dd5d861cbe2f77dba65051 /drivers | |
| parent | 9e767c280c10a14a88818dc71f0f8d8f96b642a2 (diff) | |
ehci: speed up initialization
According to EHCI specification v1.0, the controller should stabilize
the power on a port at most 20 ms after the port power bit transition.
So, we put this setting in the virtual descriptor corresponding field,
(bPwrOn2PwrGood = 10 => 10 x 2ms = 20ms), this saves about 500ms at each
controller initialization/enumeration.
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
BUG=chrome-os-partner:6344
TEST=check USB time stamp on Lumpy before and after the patch
Change-Id: Ia09f62bdb6545387e5e7386ef9095abd53a7d192
Reviewed-on: https://gerrit.chromium.org/gerrit/12491
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Stefan Reinauer <reinauer@chromium.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
Commit-Ready: Vincent Palatin <vpalatin@chromium.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/host/ehci-hcd.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index d41eea147e..6a40ac248b 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -53,7 +53,7 @@ static struct descriptor { 0x29, /* bDescriptorType: hub descriptor */ 2, /* bNrPorts -- runtime modified */ 0, /* wHubCharacteristics */ - 0xff, /* bPwrOn2PwrGood */ + 10, /* bPwrOn2PwrGood */ 0, /* bHubCntrCurrent */ {}, /* Device removable */ {} /* at most 7 ports! XXX */ |