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.
Signed-off-by: Sarah Sharp <[EMAIL PROTECTED]>
---
drivers/usb/host/ehci-hcd.c | 41 +++++++++++++++++++++++++----------------
1 files changed, 25 insertions(+), 16 deletions(-)
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 4caa6a8..b35285b 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -334,17 +334,13 @@ 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 */
@@ -354,6 +350,22 @@ 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;
@@ -404,15 +416,15 @@ 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);
@@ -421,13 +433,10 @@ 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);
--
1.5.3.4
-
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