Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 1d619f12 authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Greg Kroah-Hartman
Browse files

USB: switch ehci-hcd to new polling scheme 



Switch ehci-hcd to use the new polling scheme, which reports root
hub status changes via the interrupt handler, in an asynchronous
fashion. Doing so disables polling for status changes (whose handler is
rh_timer_func).

Tested on a Geode GX machine, which is now capable of running at =~ 5
timer interrupts per second (in the -rt tree), resulting in significant
power savings.

Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent d0532184

drivers/usb/host/ehci-hcd.c

+7 −1
Original line number Diff line number Diff line
@@ -501,6 +501,9 @@ static int ehci_run (struct usb_hcd *hcd) 
	u32			temp;

	u32			hcc_params;



	hcd->uses_new_polling = 1;

	hcd->poll_rh = 0;



	/* EHCI spec section 4.1 */

	if ((retval = ehci_reset(ehci)) != 0) {

		ehci_mem_cleanup(ehci);
@@ -574,7 +577,7 @@ static int ehci_run (struct usb_hcd *hcd) 
static irqreturn_t ehci_irq (struct usb_hcd *hcd)

{

	struct ehci_hcd		*ehci = hcd_to_ehci (hcd);

	u32			status;

	u32			status, pcd_status = 0;

	int			bh;



	spin_lock (&ehci->lock);
@@ -624,6 +627,7 @@ static irqreturn_t ehci_irq (struct usb_hcd *hcd) 
	/* remote wakeup [4.3.1] */

	if (status & STS_PCD) {

		unsigned	i = HCS_N_PORTS (ehci->hcs_params);

		pcd_status = status;



		/* resume root hub? */

		if (!(ehci_readl(ehci, &ehci->regs->command) & CMD_RUN))
@@ -670,6 +674,8 @@ dead: 
	if (bh)

		ehci_work (ehci);

	spin_unlock (&ehci->lock);

	if (pcd_status & STS_PCD)

		usb_hcd_poll_rh_status(hcd);

	return IRQ_HANDLED;

}