This patch (as1588) adjusts the locking in ehci-hcd's various halt,
shutdown, and suspend/resume pathways. We want to hold the spinlock
while writing device registers and accessing shared variables, but not
while polling in a loop.
In addition, there's no need to call ehci_work() at times when no URBs
can be active, i.e., in ehci_stop() and ehci_bus_suspend().
Finally, ehci_adjust_port_wakeup_flags() is called only in situations
where interrupts are enabled; therefore it can use spin_lock_irq
rather than spin_lock_irqsave.
Signed-off-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/host/ehci-hcd.c | 48 ++++++++++++++++++++++++++++--------------
drivers/usb/host/ehci-hub.c | 41 +++++++++++++++++++++++++----------
drivers/usb/host/ehci-tegra.c | 5 +---
3 files changed, 64 insertions(+), 30 deletions(-)
Index: usb-3.4/drivers/usb/host/ehci-hcd.c
===================================================================
--- usb-3.4.orig/drivers/usb/host/ehci-hcd.c
+++ usb-3.4/drivers/usb/host/ehci-hcd.c
@@ -167,21 +167,24 @@ static int tdi_in_host_mode (struct ehci
return (tmp & 3) == USBMODE_CM_HC;
}
-/* force HC to halt state from unknown (EHCI spec section 2.3) */
+/*
+ * Force HC to halt state from unknown (EHCI spec section 2.3).
+ * Must be called with interrupts enabled and the lock not held.
+ */
static int ehci_halt (struct ehci_hcd *ehci)
{
- u32 temp = ehci_readl(ehci, &ehci->regs->status);
+ u32 temp;
+
+ spin_lock_irq(&ehci->lock);
/* disable any irqs left enabled by previous code */
ehci_writel(ehci, 0, &ehci->regs->intr_enable);
- if (ehci_is_TDI(ehci) && tdi_in_host_mode(ehci) == 0) {
+ if (ehci_is_TDI(ehci) && !tdi_in_host_mode(ehci)) {
+ spin_unlock_irq(&ehci->lock);
return 0;
}
- if ((temp & STS_HALT) != 0)
- return 0;
-
/*
* This routine gets called during probe before ehci->command
* has been initialized, so we can't rely on its value.
@@ -190,7 +193,11 @@ static int ehci_halt (struct ehci_hcd *e
temp = ehci_readl(ehci, &ehci->regs->command);
temp &= ~(CMD_RUN | CMD_IAAD);
ehci_writel(ehci, temp, &ehci->regs->command);
- return handshake (ehci, &ehci->regs->status,
+
+ spin_unlock_irq(&ehci->lock);
+ synchronize_irq(ehci_to_hcd(ehci)->irq);
+
+ return handshake(ehci, &ehci->regs->status,
STS_HALT, STS_HALT, 16 * 125);
}
@@ -210,7 +217,10 @@ static void tdi_reset (struct ehci_hcd *
ehci_writel(ehci, tmp, &ehci->regs->usbmode);
}
-/* reset a non-running (STS_HALT == 1) controller */
+/*
+ * Reset a non-running (STS_HALT == 1) controller.
+ * Must be called with interrupts enabled and the lock not held.
+ */
static int ehci_reset (struct ehci_hcd *ehci)
{
int retval;
@@ -248,7 +258,10 @@ static int ehci_reset (struct ehci_hcd *
return retval;
}
-/* idle the controller (from running) */
+/*
+ * Idle the controller (turn off the schedules).
+ * Must be called with interrupts enabled and the lock not held.
+ */
static void ehci_quiesce (struct ehci_hcd *ehci)
{
u32 temp;
@@ -261,8 +274,10 @@ static void ehci_quiesce (struct ehci_hc
handshake(ehci, &ehci->regs->status, STS_ASS | STS_PSS, temp, 16 * 125);
/* then disable anything that's still active */
+ spin_lock_irq(&ehci->lock);
ehci->command &= ~(CMD_ASE | CMD_PSE);
ehci_writel(ehci, ehci->command, &ehci->regs->command);
+ spin_unlock_irq(&ehci->lock);
/* hardware can take 16 microframes to turn off ... */
handshake(ehci, &ehci->regs->status, STS_ASS | STS_PSS, 0, 16 * 125);
@@ -301,11 +316,14 @@ static void ehci_turn_off_all_ports(stru
/*
* Halt HC, turn off all ports, and let the BIOS use the companion controllers.
- * Should be called with ehci->lock held.
+ * Must be called with interrupts enabled and the lock not held.
*/
static void ehci_silence_controller(struct ehci_hcd *ehci)
{
ehci_halt(ehci);
+
+ spin_lock_irq(&ehci->lock);
+ ehci->rh_state = EHCI_RH_HALTED;
ehci_turn_off_all_ports(ehci);
/* make BIOS/etc use companion controller during reboot */
@@ -313,6 +331,7 @@ static void ehci_silence_controller(stru
/* unblock posted writes */
ehci_readl(ehci, &ehci->regs->configured_flag);
+ spin_unlock_irq(&ehci->lock);
}
/* ehci_shutdown kick in for silicon on any bus (not just pci, etc).
@@ -325,10 +344,11 @@ static void ehci_shutdown(struct usb_hcd
spin_lock_irq(&ehci->lock);
ehci->rh_state = EHCI_RH_STOPPING;
- ehci_silence_controller(ehci);
ehci->enabled_hrtimer_events = 0;
spin_unlock_irq(&ehci->lock);
+ ehci_silence_controller(ehci);
+
hrtimer_cancel(&ehci->hrtimer);
}
@@ -400,11 +420,11 @@ static void ehci_stop (struct usb_hcd *h
spin_lock_irq(&ehci->lock);
ehci->enabled_hrtimer_events = 0;
- ehci_quiesce(ehci);
+ spin_unlock_irq(&ehci->lock);
+ ehci_quiesce(ehci);
ehci_silence_controller(ehci);
ehci_reset (ehci);
- spin_unlock_irq(&ehci->lock);
hrtimer_cancel(&ehci->hrtimer);
remove_sysfs_files(ehci);
@@ -412,8 +432,6 @@ static void ehci_stop (struct usb_hcd *h
/* root hub is shut down separately (first, when possible) */
spin_lock_irq (&ehci->lock);
- if (ehci->async)
- ehci_work (ehci);
end_free_itds(ehci);
spin_unlock_irq (&ehci->lock);
ehci_mem_cleanup (ehci);
Index: usb-3.4/drivers/usb/host/ehci-hub.c
===================================================================
--- usb-3.4.orig/drivers/usb/host/ehci-hub.c
+++ usb-3.4/drivers/usb/host/ehci-hub.c
@@ -59,6 +59,7 @@ static void ehci_handover_companion_port
/* Give the connections some time to appear */
msleep(20);
+ spin_lock_irq(&ehci->lock);
port = HCS_N_PORTS(ehci->hcs_params);
while (port--) {
if (test_bit(port, &ehci->owned_ports)) {
@@ -70,23 +71,30 @@ static void ehci_handover_companion_port
clear_bit(port, &ehci->owned_ports);
else if (test_bit(port, &ehci->companion_ports))
ehci_writel(ehci, status & ~PORT_PE, reg);
- else
+ else {
+ spin_unlock_irq(&ehci->lock);
ehci_hub_control(hcd, SetPortFeature,
USB_PORT_FEAT_RESET, port + 1,
NULL, 0);
+ spin_lock_irq(&ehci->lock);
+ }
}
}
+ spin_unlock_irq(&ehci->lock);
if (!ehci->owned_ports)
return;
msleep(90); /* Wait for resets to complete */
+ spin_lock_irq(&ehci->lock);
port = HCS_N_PORTS(ehci->hcs_params);
while (port--) {
if (test_bit(port, &ehci->owned_ports)) {
+ spin_unlock_irq(&ehci->lock);
ehci_hub_control(hcd, GetPortStatus,
0, port + 1,
(char *) &buf, sizeof(buf));
+ spin_lock_irq(&ehci->lock);
/* The companion should now own the port,
* but if something went wrong the port must not
@@ -105,6 +113,7 @@ static void ehci_handover_companion_port
}
ehci->owned_ports = 0;
+ spin_unlock_irq(&ehci->lock);
}
static int ehci_port_change(struct ehci_hcd *ehci)
@@ -133,7 +142,6 @@ static void ehci_adjust_port_wakeup_flag
{
int port;
u32 temp;
- unsigned long flags;
/* If remote wakeup is enabled for the root hub but disabled
* for the controller, we must adjust all the port wakeup flags
@@ -143,7 +151,7 @@ static void ehci_adjust_port_wakeup_flag
if (!ehci_to_hcd(ehci)->self.root_hub->do_remote_wakeup || do_wakeup)
return;
- spin_lock_irqsave(&ehci->lock, flags);
+ spin_lock_irq(&ehci->lock);
/* clear phy low-power mode before changing wakeup flags */
if (ehci->has_hostpc) {
@@ -154,9 +162,9 @@ static void ehci_adjust_port_wakeup_flag
temp = ehci_readl(ehci, hostpc_reg);
ehci_writel(ehci, temp & ~HOSTPC_PHCD, hostpc_reg);
}
- spin_unlock_irqrestore(&ehci->lock, flags);
+ spin_unlock_irq(&ehci->lock);
msleep(5);
- spin_lock_irqsave(&ehci->lock, flags);
+ spin_lock_irq(&ehci->lock);
}
port = HCS_N_PORTS(ehci->hcs_params);
@@ -194,7 +202,7 @@ static void ehci_adjust_port_wakeup_flag
if (!suspending && ehci_port_change(ehci))
usb_hcd_resume_root_hub(ehci_to_hcd(ehci));
- spin_unlock_irqrestore(&ehci->lock, flags);
+ spin_unlock_irq(&ehci->lock);
}
static int ehci_bus_suspend (struct usb_hcd *hcd)
@@ -209,6 +217,9 @@ static int ehci_bus_suspend (struct usb_
if (time_before (jiffies, ehci->next_statechange))
msleep(5);
+ /* stop the schedules */
+ ehci_quiesce(ehci);
+
spin_lock_irq (&ehci->lock);
/* Once the controller is stopped, port resumes that are already
@@ -224,10 +235,6 @@ static int ehci_bus_suspend (struct usb_
}
}
- /* stop schedules, clean any completed work */
- ehci_quiesce(ehci);
- ehci_work(ehci);
-
/* Unlike other USB host controller types, EHCI doesn't have
* any notion of "global" or bus-wide suspend. The driver has
* to manually suspend all the active unsuspended ports, and
@@ -289,6 +296,7 @@ static int ehci_bus_suspend (struct usb_
"succeeded" : "failed");
}
}
+ spin_unlock_irq(&ehci->lock);
/* Apparently some devices need a >= 1-uframe delay here */
if (ehci->bus_suspended)
@@ -296,6 +304,8 @@ static int ehci_bus_suspend (struct usb_
/* turn off now-idle HC */
ehci_halt (ehci);
+
+ spin_lock_irq(&ehci->lock);
ehci->rh_state = EHCI_RH_SUSPENDED;
end_unlink_async(ehci);
@@ -424,13 +434,14 @@ static int ehci_bus_resume (struct usb_h
}
ehci->next_statechange = jiffies + msecs_to_jiffies(5);
+ spin_unlock_irq(&ehci->lock);
+
+ ehci_handover_companion_ports(ehci);
/* Now we can safely re-enable irqs */
ehci_writel(ehci, INTR_MASK, &ehci->regs->intr_enable);
(void) ehci_readl(ehci, &ehci->regs->intr_enable);
- spin_unlock_irq (&ehci->lock);
- ehci_handover_companion_ports(ehci);
return 0;
}
@@ -1018,7 +1029,9 @@ static int ehci_hub_control (
case USB_PORT_FEAT_TEST:
if (!selector || selector > 5)
goto error;
+ spin_unlock_irqrestore(&ehci->lock, flags);
ehci_quiesce(ehci);
+ spin_lock_irqsave(&ehci->lock, flags);
/* Put all enabled ports into suspend */
while (ports--) {
@@ -1030,7 +1043,11 @@ static int ehci_hub_control (
ehci_writel(ehci, temp | PORT_SUSPEND,
sreg);
}
+
+ spin_unlock_irqrestore(&ehci->lock, flags);
ehci_halt(ehci);
+ spin_lock_irqsave(&ehci->lock, flags);
+
temp = ehci_readl(ehci, status_reg);
temp |= selector << 16;
ehci_writel(ehci, temp, status_reg);
Index: usb-3.4/drivers/usb/host/ehci-tegra.c
===================================================================
--- usb-3.4.orig/drivers/usb/host/ehci-tegra.c
+++ usb-3.4/drivers/usb/host/ehci-tegra.c
@@ -444,12 +444,11 @@ static int controller_suspend(struct dev
if (time_before(jiffies, ehci->next_statechange))
msleep(10);
- spin_lock_irqsave(&ehci->lock, flags);
+ ehci_halt(ehci);
+ spin_lock_irqsave(&ehci->lock, flags);
tegra->port_speed = (readl(&hw->port_status[0]) >> 26) & 0x3;
- ehci_halt(ehci);
clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
-
spin_unlock_irqrestore(&ehci->lock, flags);
tegra_ehci_power_down(hcd);
--
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