From vikram.pandita@ti.com Mon Oct 27 11:43:00 2008 From: Vikram Pandita Date: Fri, 24 Oct 2008 23:41:30 +0530 Subject: USB: Avoid 20ms delay in EHCI resume To: Alan Stern , "linux-usb@vger.kernel.org" Message-ID: From: Vikram Pandita For function ehci_bus_resume() - Added flag resume_needed No need to wait for 20ms if no port was suspended - Change mdelay to msleep - release and reacquire the spinlock around mdelay Signed-off-by: vikram pandita Acked-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hub.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -194,6 +194,7 @@ static int ehci_bus_resume (struct usb_h u32 temp; u32 power_okay; int i; + u8 resume_needed = 0; if (time_before (jiffies, ehci->next_statechange)) msleep(5); @@ -228,7 +229,9 @@ static int ehci_bus_resume (struct usb_h /* Some controller/firmware combinations need a delay during which * they set up the port statuses. See Bugzilla #8190. */ - mdelay(8); + spin_unlock_irq(&ehci->lock); + msleep(8); + spin_lock_irq(&ehci->lock); /* manually resume the ports we suspended during bus_suspend() */ i = HCS_N_PORTS (ehci->hcs_params); @@ -236,12 +239,21 @@ static int ehci_bus_resume (struct usb_h temp = ehci_readl(ehci, &ehci->regs->port_status [i]); temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS); if (test_bit(i, &ehci->bus_suspended) && - (temp & PORT_SUSPEND)) + (temp & PORT_SUSPEND)) { temp |= PORT_RESUME; + resume_needed = 1; + } ehci_writel(ehci, temp, &ehci->regs->port_status [i]); } + + /* msleep for 20ms only if code is trying to resume port */ + if (resume_needed) { + spin_unlock_irq(&ehci->lock); + msleep(20); + spin_lock_irq(&ehci->lock); + } + i = HCS_N_PORTS (ehci->hcs_params); - mdelay (20); while (i--) { temp = ehci_readl(ehci, &ehci->regs->port_status [i]); if (test_bit(i, &ehci->bus_suspended) &&