From 21da84a89312dd8d014ca3352d1ab5c2279ec548 Mon Sep 17 00:00:00 2001 From: Sarah Sharp Date: Tue, 8 Apr 2008 14:30:18 -0700 Subject: [PATCH] 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 Signed-off-by: David Brownell Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-hcd.c | 41 ++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 16 deletions(-) diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index a02dcff5eb21..369a8a5ea7bb 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);