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authorSarah Sharp <sarah.a.sharp@intel.com>2008-04-08 14:30:18 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2008-04-24 21:16:49 -0700
commit21da84a89312dd8d014ca3352d1ab5c2279ec548 (patch)
tree148e28526110b173d73903191ed0166c5618c683 /drivers/usb
parent3cf2723432dd27402a4a4941ad2d04eae5dd639c (diff)
USB: ehci shutdown refactored
This patch refactors some shutdown code so it can be shared between ehci_stop() and ehci_shutdown(). This also fixes a couple potential bugs: - ehci_shutdown() was not locking ehci->lock before halting the HC. - ehci_shutdown() didn't disable the watchdog and IAA timers. - ehci_stop() was resetting the host controller when it may have been running, which the EHCI spec says "may result in undefined behavior". ehci_stop() was calling port_power() to turn off the ports, which waited 20ms after applying the port change. The msleep was for the case where the HC might take 20ms to turn the ports on; since we're shutting them off, we can avoid the msleep and just use ehci_turn_off_ports(). ehci_stop() doesn't need to clear the intr_enable register or revert ownership of the companion controllers to the BIOS, because the host controller reset should have done that. There might be a buggy host controller that doesn't follow the reset rules, but for now we assume it's redundant code and remove it. [ A subsequent patch will cancel the timers later ... this version carries forward existing bugs where timers could get re-armed after they're canceled. ] Signed-off-by: Sarah Sharp <sarah.a.sharp@intel.com> Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/host/ehci-hcd.c41
1 files changed, 25 insertions, 16 deletions
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index a02dcff5eb2..369a8a5ea7b 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -331,17 +331,13 @@ static void ehci_turn_off_all_ports(struct ehci_hcd *ehci)
&ehci->regs->port_status[port]);
}
-/* ehci_shutdown kick in for silicon on any bus (not just pci, etc).
- * This forcibly disables dma and IRQs, helping kexec and other cases
- * where the next system software may expect clean state.
+/*
+ * Halt HC, turn off all ports, and let the BIOS use the companion controllers.
+ * Should be called with ehci->lock held.
*/
-static void
-ehci_shutdown (struct usb_hcd *hcd)
+static void ehci_silence_controller(struct ehci_hcd *ehci)
{
- struct ehci_hcd *ehci;
-
- ehci = hcd_to_ehci (hcd);
- (void) ehci_halt (ehci);
+ ehci_halt(ehci);
ehci_turn_off_all_ports(ehci);
/* make BIOS/etc use companion controller during reboot */
@@ -351,6 +347,22 @@ ehci_shutdown (struct usb_hcd *hcd)
ehci_readl(ehci, &ehci->regs->configured_flag);
}
+/* ehci_shutdown kick in for silicon on any bus (not just pci, etc).
+ * This forcibly disables dma and IRQs, helping kexec and other cases
+ * where the next system software may expect clean state.
+ */
+static void ehci_shutdown(struct usb_hcd *hcd)
+{
+ struct ehci_hcd *ehci = hcd_to_ehci(hcd);
+
+ del_timer_sync(&ehci->watchdog);
+ del_timer_sync(&ehci->iaa_watchdog);
+
+ spin_lock_irq(&ehci->lock);
+ ehci_silence_controller(ehci);
+ spin_unlock_irq(&ehci->lock);
+}
+
static void ehci_port_power (struct ehci_hcd *ehci, int is_on)
{
unsigned port;
@@ -401,15 +413,15 @@ static void ehci_work (struct ehci_hcd *ehci)
timer_action (ehci, TIMER_IO_WATCHDOG);
}
+/*
+ * Called when the ehci_hcd module is removed.
+ */
static void ehci_stop (struct usb_hcd *hcd)
{
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
ehci_dbg (ehci, "stop\n");
- /* Turn off port power on all root hub ports. */
- ehci_port_power (ehci, 0);
-
/* no more interrupts ... */
del_timer_sync (&ehci->watchdog);
del_timer_sync(&ehci->iaa_watchdog);
@@ -418,13 +430,10 @@ static void ehci_stop (struct usb_hcd *hcd)
if (HC_IS_RUNNING (hcd->state))
ehci_quiesce (ehci);
+ ehci_silence_controller(ehci);
ehci_reset (ehci);
- ehci_writel(ehci, 0, &ehci->regs->intr_enable);
spin_unlock_irq(&ehci->lock);
- /* let companion controllers work when we aren't */
- ehci_writel(ehci, 0, &ehci->regs->configured_flag);
-
remove_companion_file(ehci);
remove_debug_files (ehci);