diff options
author | Sarah Sharp <sarah.a.sharp@intel.com> | 2008-04-08 21:30:18 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-04-25 04:16:49 (GMT) |
commit | 21da84a89312dd8d014ca3352d1ab5c2279ec548 (patch) | |
tree | 148e28526110b173d73903191ed0166c5618c683 /drivers/usb | |
parent | 3cf2723432dd27402a4a4941ad2d04eae5dd639c (diff) | |
download | linux-fsl-qoriq-21da84a89312dd8d014ca3352d1ab5c2279ec548.tar.xz |
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.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 a02dcff..369a8a5 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); |