Re: [linux-pm] [PATCH v2] [RFC] ehci: Disable wake on overcurrent(WKOC_E) and disconnect (WKDISC_E)

From: Alan Stern
Date: Mon May 10 2010 - 17:05:41 EST

On Mon, 10 May 2010, Du, Alek wrote:

> Alan,
>
> The following patch (based on your previous two patches) works for me, could you
> help to review and test on your machine? Basically, this will only affect those
> "has_hostpc" HCDs.

Based on your suggestion, I completely redid both of my patches. They
are now combined into a single patch, which is meant to go on top of
the patch you submitted this morning. It adds the stuff we talked
about, and it cleans up some of the changes you made.

Does it look good to you?

Alan Stern



Index: usb-2.6/drivers/usb/host/ehci-hub.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-hub.c
+++ usb-2.6/drivers/usb/host/ehci-hub.c
@@ -106,12 +106,72 @@ static void ehci_handover_companion_port
ehci->owned_ports = 0;
}

+static void ehci_adjust_port_wakeup_flags(struct ehci_hcd *ehci, bool resuming)
+{
+ int port;
+ u32 temp;
+
+ /* If remote wakeup is enabled for the root hub but disabled
+ * for the controller, we must adjust all the port wakeup flags.
+ */
+ if (!ehci_to_hcd(ehci)->self.root_hub->do_remote_wakeup ||
+ device_may_wakeup(ehci_to_hcd(ehci)->self.controller))
+ return;
+
+ /* clear phy low-power mode before changing wakeup flags */
+ if (ehci->has_hostpc) {
+ port = HCS_N_PORTS(ehci->hcs_params);
+ while (port--) {
+ u32 __iomem *hostpc_reg;
+
+ hostpc_reg = (u32 __iomem *)((u8 *) ehci->regs
+ + HOSTPC0 + 4 * port);
+ temp = ehci_readl(ehci, hostpc_reg);
+ ehci_writel(ehci, temp & ~HOSTPC_PHCD, hostpc_reg);
+ }
+ msleep(5);
+ }
+
+ port = HCS_N_PORTS(ehci->hcs_params);
+ while (port--) {
+ u32 __iomem *reg = &ehci->regs->port_status[port];
+ u32 t1 = ehci_readl(ehci, reg) & ~PORT_RWC_BITS;
+ u32 t2 = t1 & ~PORT_WAKE_BITS;
+
+ /* If we are suspending the controller, clear the flags.
+ * If we are resuming the controller, set the wakeup flags.
+ */
+ if (resuming) {
+ if (t1 & PORT_CONNECT)
+ t2 |= PORT_WKOC_E | PORT_WKDISC_E;
+ else
+ t2 |= PORT_WKOC_E | PORT_WKCONN_E;
+ }
+ ehci_vdbg(ehci, "port %d, %08x -> %08x\n",
+ port + 1, t1, t2);
+ ehci_writel(ehci, t2, reg);
+ }
+
+ /* enter phy low-power mode again */
+ if (ehci->has_hostpc) {
+ port = HCS_N_PORTS(ehci->hcs_params);
+ while (port--) {
+ u32 __iomem *hostpc_reg;
+
+ hostpc_reg = (u32 __iomem *)((u8 *) ehci->regs
+ + HOSTPC0 + 4 * port);
+ temp = ehci_readl(ehci, hostpc_reg);
+ ehci_writel(ehci, temp | HOSTPC_PHCD, hostpc_reg);
+ }
+ }
+}
+
static int ehci_bus_suspend (struct usb_hcd *hcd)
{
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
int port;
int mask;
- u32 __iomem *hostpc_reg = NULL;
+ int changed;

ehci_dbg(ehci, "suspend root hub\n");

@@ -155,15 +215,13 @@ static int ehci_bus_suspend (struct usb_
*/
ehci->bus_suspended = 0;
ehci->owned_ports = 0;
+ changed = 0;
port = HCS_N_PORTS(ehci->hcs_params);
while (port--) {
u32 __iomem *reg = &ehci->regs->port_status [port];
u32 t1 = ehci_readl(ehci, reg) & ~PORT_RWC_BITS;
- u32 t2 = t1;
+ u32 t2 = t1 & ~PORT_WAKE_BITS;

- if (ehci->has_hostpc)
- hostpc_reg = (u32 __iomem *)((u8 *)ehci->regs
- + HOSTPC0 + 4 * (port & 0xff));
/* keep track of which ports we suspend */
if (t1 & PORT_OWNER)
set_bit(port, &ehci->owned_ports);
@@ -172,40 +230,45 @@ static int ehci_bus_suspend (struct usb_
set_bit(port, &ehci->bus_suspended);
}

- /* enable remote wakeup on all ports */
+ /* enable remote wakeup on all ports, if told to do so */
if (hcd->self.root_hub->do_remote_wakeup) {
/* only enable appropriate wake bits, otherwise the
* hardware can not go phy low power mode. If a race
* condition happens here(connection change during bits
* set), the port change detection will finally fix it.
*/
- if (t1 & PORT_CONNECT) {
+ if (t1 & PORT_CONNECT)
t2 |= PORT_WKOC_E | PORT_WKDISC_E;
- t2 &= ~PORT_WKCONN_E;
- } else {
+ else
t2 |= PORT_WKOC_E | PORT_WKCONN_E;
- t2 &= ~PORT_WKDISC_E;
- }
- } else
- t2 &= ~PORT_WAKE_BITS;
+ }

if (t1 != t2) {
ehci_vdbg (ehci, "port %d, %08x -> %08x\n",
port + 1, t1, t2);
ehci_writel(ehci, t2, reg);
- if (hostpc_reg) {
- u32 t3;
+ changed = 1;
+ }
+ }

- spin_unlock_irq(&ehci->lock);
- msleep(5);/* 5ms for HCD enter low pwr mode */
- spin_lock_irq(&ehci->lock);
- t3 = ehci_readl(ehci, hostpc_reg);
- ehci_writel(ehci, t3 | HOSTPC_PHCD, hostpc_reg);
- t3 = ehci_readl(ehci, hostpc_reg);
- ehci_dbg(ehci, "Port%d phy low pwr mode %s\n",
+ if (changed && ehci->has_hostpc) {
+ spin_unlock_irq(&ehci->lock);
+ msleep(5); /* 5 ms for HCD to enter low-power mode */
+ spin_lock_irq(&ehci->lock);
+
+ port = HCS_N_PORTS(ehci->hcs_params);
+ while (port--) {
+ u32 __iomem *hostpc_reg;
+ u32 t3;
+
+ hostpc_reg = (u32 __iomem *)((u8 *) ehci->regs
+ + HOSTPC0 + 4 * port);
+ t3 = ehci_readl(ehci, hostpc_reg);
+ ehci_writel(ehci, t3 | HOSTPC_PHCD, hostpc_reg);
+ t3 = ehci_readl(ehci, hostpc_reg);
+ ehci_dbg(ehci, "Port %d phy low-power mode %s\n",
port, (t3 & HOSTPC_PHCD) ?
"succeeded" : "failed");
- }
}
}

@@ -291,19 +354,28 @@ static int ehci_bus_resume (struct usb_h
msleep(8);
spin_lock_irq(&ehci->lock);

+ /* clear phy low-power mode before resume */
+ if (ehci->bus_suspended && ehci->has_hostpc) {
+ i = HCS_N_PORTS (ehci->hcs_params);
+ while (i--) {
+ if (test_bit(i, &ehci->bus_suspended)) {
+ u32 __iomem *hostpc_reg;
+
+ hostpc_reg = (u32 __iomem *)((u8 *) ehci->regs
+ + HOSTPC0 + 4 * i);
+ temp = ehci_readl(ehci, hostpc_reg);
+ ehci_writel(ehci, temp & ~HOSTPC_PHCD,
+ hostpc_reg);
+ }
+ }
+ spin_unlock_irq(&ehci->lock);
+ msleep(5);
+ spin_lock_irq(&ehci->lock);
+ }
+
/* manually resume the ports we suspended during bus_suspend() */
i = HCS_N_PORTS (ehci->hcs_params);
while (i--) {
- /* clear phy low power mode before resume */
- if (ehci->has_hostpc) {
- u32 __iomem *hostpc_reg =
- (u32 __iomem *)((u8 *)ehci->regs
- + HOSTPC0 + 4 * (i & 0xff));
- temp = ehci_readl(ehci, hostpc_reg);
- ehci_writel(ehci, temp & ~HOSTPC_PHCD,
- hostpc_reg);
- mdelay(5);
- }
temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
if (test_bit(i, &ehci->bus_suspended) &&
@@ -685,23 +757,25 @@ static int ehci_hub_control (
goto error;
if (ehci->no_selective_suspend)
break;
- if (temp & PORT_SUSPEND) {
- if ((temp & PORT_PE) == 0)
- goto error;
- /* clear phy low power mode before resume */
- if (hostpc_reg) {
- temp1 = ehci_readl(ehci, hostpc_reg);
- ehci_writel(ehci, temp1 & ~HOSTPC_PHCD,
- hostpc_reg);
- mdelay(5);
- }
- /* resume signaling for 20 msec */
- temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
- ehci_writel(ehci, temp | PORT_RESUME,
- status_reg);
- ehci->reset_done [wIndex] = jiffies
- + msecs_to_jiffies (20);
+ if (!(temp & PORT_SUSPEND))
+ break;
+ if ((temp & PORT_PE) == 0)
+ goto error;
+
+ /* clear phy low-power mode before resume */
+ if (hostpc_reg) {
+ temp1 = ehci_readl(ehci, hostpc_reg);
+ ehci_writel(ehci, temp1 & ~HOSTPC_PHCD,
+ hostpc_reg);
+ spin_unlock_irqrestore(&ehci->lock, flags);
+ msleep(5);/* wait to leave low-power mode */
+ spin_lock_irqsave(&ehci->lock, flags);
}
+ /* resume signaling for 20 msec */
+ temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
+ ehci_writel(ehci, temp | PORT_RESUME, status_reg);
+ ehci->reset_done[wIndex] = jiffies
+ + msecs_to_jiffies(20);
break;
case USB_PORT_FEAT_C_SUSPEND:
clear_bit(wIndex, &ehci->port_c_suspend);
Index: usb-2.6/drivers/usb/host/ehci-pci.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-pci.c
+++ usb-2.6/drivers/usb/host/ehci-pci.c
@@ -287,23 +287,15 @@ static int ehci_pci_suspend(struct usb_h
msleep(10);

/* Root hub was already suspended. Disable irq emission and
- * mark HW unaccessible, bail out if RH has been resumed. Use
- * the spinlock to properly synchronize with possible pending
- * RH suspend or resume activity.
- *
- * This is still racy as hcd->state is manipulated outside of
- * any locks =P But that will be a different fix.
+ * mark HW unaccessible. The PM and USB cores make sure that
+ * the root hub is either suspended or stopped.
*/
spin_lock_irqsave (&ehci->lock, flags);
- if (hcd->state != HC_STATE_SUSPENDED) {
- rc = -EINVAL;
- goto bail;
- }
+ ehci_adjust_port_wakeup_flags(ehci, false);
ehci_writel(ehci, 0, &ehci->regs->intr_enable);
(void)ehci_readl(ehci, &ehci->regs->intr_enable);

clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
- bail:
spin_unlock_irqrestore (&ehci->lock, flags);

// could save FLADJ in case of Vaux power loss
@@ -333,6 +325,7 @@ static int ehci_pci_resume(struct usb_hc
!hibernated) {
int mask = INTR_MASK;

+ ehci_adjust_port_wakeup_flags(ehci, true);
if (!hcd->self.root_hub->do_remote_wakeup)
mask &= ~STS_PCD;
ehci_writel(ehci, mask, &ehci->regs->intr_enable);
Index: usb-2.6/drivers/usb/host/ehci-au1xxx.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-au1xxx.c
+++ usb-2.6/drivers/usb/host/ehci-au1xxx.c
@@ -224,26 +224,17 @@ static int ehci_hcd_au1xxx_drv_suspend(s
msleep(10);

/* Root hub was already suspended. Disable irq emission and
- * mark HW unaccessible, bail out if RH has been resumed. Use
- * the spinlock to properly synchronize with possible pending
- * RH suspend or resume activity.
- *
- * This is still racy as hcd->state is manipulated outside of
- * any locks =P But that will be a different fix.
+ * mark HW unaccessible. The PM and USB cores make sure that
+ * the root hub is either suspended or stopped.
*/
spin_lock_irqsave(&ehci->lock, flags);
- if (hcd->state != HC_STATE_SUSPENDED) {
- rc = -EINVAL;
- goto bail;
- }
+ ehci_adjust_port_wakeup_flags(ehci, false);
ehci_writel(ehci, 0, &ehci->regs->intr_enable);
(void)ehci_readl(ehci, &ehci->regs->intr_enable);

clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);

au1xxx_stop_ehc();
-
-bail:
spin_unlock_irqrestore(&ehci->lock, flags);

// could save FLADJ in case of Vaux power loss
@@ -273,6 +264,7 @@ static int ehci_hcd_au1xxx_drv_resume(st
if (ehci_readl(ehci, &ehci->regs->configured_flag) == FLAG_CF) {
int mask = INTR_MASK;

+ ehci_adjust_port_wakeup_flags(ehci, true);
if (!hcd->self.root_hub->do_remote_wakeup)
mask &= ~STS_PCD;
ehci_writel(ehci, mask, &ehci->regs->intr_enable);
Index: usb-2.6/drivers/usb/host/ehci-fsl.c
===================================================================
--- usb-2.6.orig/drivers/usb/host/ehci-fsl.c
+++ usb-2.6/drivers/usb/host/ehci-fsl.c
@@ -313,6 +313,7 @@ static int ehci_fsl_drv_suspend(struct d
struct ehci_fsl *ehci_fsl = hcd_to_ehci_fsl(hcd);
void __iomem *non_ehci = hcd->regs;

+ ehci_adjust_port_wakeup_flags(ehci, false);
if (!fsl_deep_sleep())
return 0;

@@ -327,6 +328,7 @@ static int ehci_fsl_drv_resume(struct de
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
void __iomem *non_ehci = hcd->regs;

+ ehci_adjust_port_wakeup_flags(ehci, true);
if (!fsl_deep_sleep())
return 0;


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