From david-b@pacbell.net Wed Aug 31 11:05:47 2005
From: David Brownell <david-b@pacbell.net>
Subject: USB: relax usbcore reset timings
Date: Wed, 31 Aug 2005 10:41:44 -0700
Cc: Greg KH <greg@kroah.com>
Message-Id: <200508311041.44489.david-b@pacbell.net>
This appears to help some folk, please merge.
This patch relaxes reset timings. There are some reports that it
helps make enumeration work better on some high speed devices.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/usb/core/hub.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
--- gregkh-2.6.orig/drivers/usb/core/hub.c 2005-09-12 11:01:57.000000000 -0700
+++ gregkh-2.6/drivers/usb/core/hub.c 2005-09-12 11:02:06.000000000 -0700
@@ -435,6 +435,7 @@ void usb_hub_tt_clear_buffer (struct usb
static void hub_power_on(struct usb_hub *hub)
{
int port1;
+ unsigned pgood_delay = hub->descriptor->bPwrOn2PwrGood * 2;
/* if hub supports power switching, enable power on each port */
if ((hub->descriptor->wHubCharacteristics & HUB_CHAR_LPSM) < 2) {
@@ -444,8 +445,8 @@ static void hub_power_on(struct usb_hub
USB_PORT_FEAT_POWER);
}
- /* Wait for power to be enabled */
- msleep(hub->descriptor->bPwrOn2PwrGood * 2);
+ /* Wait at least 100 msec for power to become stable */
+ msleep(max(pgood_delay, (unsigned) 100));
}
static void hub_quiesce(struct usb_hub *hub)
@@ -1469,8 +1470,8 @@ static int hub_port_reset(struct usb_hub
/* return on disconnect or reset */
switch (status) {
case 0:
- /* TRSTRCY = 10 ms */
- msleep(10);
+ /* TRSTRCY = 10 ms; plus some extra */
+ msleep(10 + 40);
/* FALL THROUGH */
case -ENOTCONN:
case -ENODEV: