diff options
Diffstat (limited to 'drivers/usb/host/uhci-hub.c')
| -rw-r--r-- | drivers/usb/host/uhci-hub.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/usb/host/uhci-hub.c b/drivers/usb/host/uhci-hub.c index c545ef92fe29..16fb72eb6fc9 100644 --- a/drivers/usb/host/uhci-hub.c +++ b/drivers/usb/host/uhci-hub.c @@ -84,6 +84,7 @@ static void uhci_finish_suspend(struct uhci_hcd *uhci, int port, unsigned long port_addr) { int status; + int i; if (inw(port_addr) & (USBPORTSC_SUSP | USBPORTSC_RD)) { CLR_RH_PORTSTAT(USBPORTSC_SUSP | USBPORTSC_RD); @@ -92,9 +93,14 @@ static void uhci_finish_suspend(struct uhci_hcd *uhci, int port, /* The controller won't actually turn off the RD bit until * it has had a chance to send a low-speed EOP sequence, - * which takes 3 bit times (= 2 microseconds). We'll delay - * slightly longer for good luck. */ - udelay(4); + * which is supposed to take 3 bit times (= 2 microseconds). + * Experiments show that some controllers take longer, so + * we'll poll for completion. */ + for (i = 0; i < 10; ++i) { + if (!(inw(port_addr) & USBPORTSC_RD)) + break; + udelay(1); + } } clear_bit(port, &uhci->resuming_ports); } |