USB: OHCI: Remove USB bus reset delay from OHCI handover code

Paul pointed out that the 50-ms sleep during OHCI initialization takes
up a large fraction of a system's boot time.  Things get worse when
there are two OHCI controllers present, each requiring 50 ms.

However, there really is no need to send a 50-ms reset signal out all
the root-hub ports during initialization.  The ports themselves will
be disabled, and the only way to enable a port is to reset it.
Therefore all attached USB devices will receive a proper reset in any
case.  The controller reset does not need to be long enough to reset
those other devices, so the 50-ms delay isn't necessary.

Without the delay, there is no remaining incentive for skipping the
reset when the controller is already in the RESET state.  This patch
removes the test, issuing the command unconditionally, and removes the
following delay.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Suggested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Tested-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 3625a5c1a41b81c88176bcc6a0b9e5c94bf4d59a..3ce71cbfbb586abe275284d347b25447e375e2e6 100644 (file)
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -783,15 +783,9 @@ static void quirk_usb_handoff_ohci(struct pci_dev *pdev)
        /* disable interrupts */
        writel((u32) ~0, base + OHCI_INTRDISABLE);
 
-       /* Reset the USB bus, if the controller isn't already in RESET */
-       if (control & OHCI_HCFS) {
-               /* Go into RESET, preserving RWC (and possibly IR) */
-               writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL);
-               readl(base + OHCI_CONTROL);
-
-               /* drive bus reset for at least 50 ms (7.1.7.5) */
-               msleep(50);
-       }
+       /* Go into the USB_RESET state, preserving RWC (and possibly IR) */
+       writel(control & OHCI_CTRL_MASK, base + OHCI_CONTROL);
+       readl(base + OHCI_CONTROL);
 
        /* software reset of the controller, preserving HcFmInterval */
        if (!no_fminterval)