[PATCH] USB: relax usbcore reset timings
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>
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index c5520829..a12cab5 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -435,6 +435,7 @@
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 @@
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 @@
/* 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: