USB: EHCI, OHCI: handover changes
This patch (as887) changes the way ehci-hcd and ohci-hcd handle a loss
of VBUS power during suspend. In order for the USB-persist facility
to work correctly, it is necessary for low- and full-speed devices
attached to a high-speed port to be handed back to the companion
controller during resume processing.
This entails three changes: adding code to ehci-hcd to perform the
handover, removing code from ohci-hcd to turn off ports during
root-hub reinit, and adding code to ohci-hcd to turn on ports during
PCI controller resume. (Other bus glue resume methods for platforms
supporting high-speed controllers would need a similar change, if any
existed.)
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 99ab31e..b5a7aa9 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -399,6 +399,8 @@
is_on ? SetPortFeature : ClearPortFeature,
USB_PORT_FEAT_POWER,
port--, NULL, 0);
+ /* Flush those writes */
+ ehci_readl(ehci, &ehci->regs->command);
msleep(20);
}
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index f4d301b..3e80de7 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -28,6 +28,87 @@
/*-------------------------------------------------------------------------*/
+#ifdef CONFIG_USB_PERSIST
+
+static int ehci_hub_control(
+ struct usb_hcd *hcd,
+ u16 typeReq,
+ u16 wValue,
+ u16 wIndex,
+ char *buf,
+ u16 wLength
+);
+
+/* After a power loss, ports that were owned by the companion must be
+ * reset so that the companion can still own them.
+ */
+static void ehci_handover_companion_ports(struct ehci_hcd *ehci)
+{
+ u32 __iomem *reg;
+ u32 status;
+ int port;
+ __le32 buf;
+ struct usb_hcd *hcd = ehci_to_hcd(ehci);
+
+ if (!ehci->owned_ports)
+ return;
+
+ /* Give the connections some time to appear */
+ msleep(20);
+
+ port = HCS_N_PORTS(ehci->hcs_params);
+ while (port--) {
+ if (test_bit(port, &ehci->owned_ports)) {
+ reg = &ehci->regs->port_status[port];
+ status = ehci_readl(ehci, reg);
+
+ /* Port already owned by companion? */
+ if (status & PORT_OWNER)
+ clear_bit(port, &ehci->owned_ports);
+ else
+ ehci_hub_control(hcd, SetPortFeature,
+ USB_PORT_FEAT_RESET, port + 1,
+ NULL, 0);
+ }
+ }
+
+ if (!ehci->owned_ports)
+ return;
+ msleep(90); /* Wait for resets to complete */
+
+ port = HCS_N_PORTS(ehci->hcs_params);
+ while (port--) {
+ if (test_bit(port, &ehci->owned_ports)) {
+ ehci_hub_control(hcd, GetPortStatus,
+ 0, port + 1,
+ (char *) &buf, sizeof(buf));
+
+ /* The companion should now own the port,
+ * but if something went wrong the port must not
+ * remain enabled.
+ */
+ reg = &ehci->regs->port_status[port];
+ status = ehci_readl(ehci, reg) & ~PORT_RWC_BITS;
+ if (status & PORT_OWNER)
+ ehci_writel(ehci, status | PORT_CSC, reg);
+ else {
+ ehci_dbg(ehci, "failed handover port %d: %x\n",
+ port + 1, status);
+ ehci_writel(ehci, status & ~PORT_PE, reg);
+ }
+ }
+ }
+
+ ehci->owned_ports = 0;
+}
+
+#else /* CONFIG_USB_PERSIST */
+
+static inline void ehci_handover_companion_ports(struct ehci_hcd *ehci)
+{ }
+
+#endif
+
#ifdef CONFIG_PM
static int ehci_bus_suspend (struct usb_hcd *hcd)
@@ -60,14 +141,16 @@
* then manually resume them in the bus_resume() routine.
*/
ehci->bus_suspended = 0;
+ ehci->owned_ports = 0;
while (port--) {
u32 __iomem *reg = &ehci->regs->port_status [port];
u32 t1 = ehci_readl(ehci, reg) & ~PORT_RWC_BITS;
u32 t2 = t1;
/* keep track of which ports we suspend */
- if ((t1 & PORT_PE) && !(t1 & PORT_OWNER) &&
- !(t1 & PORT_SUSPEND)) {
+ if (t1 & PORT_OWNER)
+ set_bit(port, &ehci->owned_ports);
+ else if ((t1 & PORT_PE) && !(t1 & PORT_SUSPEND)) {
t2 |= PORT_SUSPEND;
set_bit(port, &ehci->bus_suspended);
}
@@ -108,6 +191,7 @@
{
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
u32 temp;
+ u32 power_okay;
int i;
if (time_before (jiffies, ehci->next_statechange))
@@ -120,8 +204,9 @@
* the last user of the controller, not reset/pm hardware keeping
* state we gave to it.
*/
- temp = ehci_readl(ehci, &ehci->regs->intr_enable);
- ehci_dbg(ehci, "resume root hub%s\n", temp ? "" : " after power loss");
+ power_okay = ehci_readl(ehci, &ehci->regs->intr_enable);
+ ehci_dbg(ehci, "resume root hub%s\n",
+ power_okay ? "" : " after power loss");
/* at least some APM implementations will try to deliver
* IRQs right away, so delay them until we're ready.
@@ -184,6 +269,9 @@
ehci_writel(ehci, INTR_MASK, &ehci->regs->intr_enable);
spin_unlock_irq (&ehci->lock);
+
+ if (!power_okay)
+ ehci_handover_companion_ports(ehci);
return 0;
}
@@ -448,7 +536,8 @@
) {
struct ehci_hcd *ehci = hcd_to_ehci (hcd);
int ports = HCS_N_PORTS (ehci->hcs_params);
- u32 __iomem *status_reg = &ehci->regs->port_status[wIndex - 1];
+ u32 __iomem *status_reg = &ehci->regs->port_status[
+ (wIndex & 0xff) - 1];
u32 temp, status;
unsigned long flags;
int retval = 0;
diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index 966965f..a7816e3 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -312,13 +312,14 @@
ehci_work(ehci);
spin_unlock_irq(&ehci->lock);
- /* here we "know" root ports should always stay powered */
- ehci_port_power(ehci, 1);
-
ehci_writel(ehci, ehci->command, &ehci->regs->command);
ehci_writel(ehci, FLAG_CF, &ehci->regs->configured_flag);
ehci_readl(ehci, &ehci->regs->command); /* unblock posted writes */
+ /* here we "know" root ports should always stay powered */
+ ehci_port_power(ehci, 1);
+ ehci_handover_companion_ports(ehci);
+
hcd->state = HC_STATE_SUSPENDED;
return 0;
}
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 6ef9d77..4d61710 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -96,11 +96,14 @@
/* per root hub port */
unsigned long reset_done [EHCI_MAX_ROOT_PORTS];
+
/* bit vectors (one bit per port) */
unsigned long bus_suspended; /* which ports were
already suspended at the start of a bus suspend */
unsigned long companion_ports; /* which ports are
dedicated to the companion controller */
+ unsigned long owned_ports; /* which ports are
+ owned by the companion during a bus suspend */
/* per-HC memory pools (could be per-bus, but ...) */
struct dma_pool *qh_pool; /* qh per active urb */
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index a66637e..ce05e5f 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -510,15 +510,7 @@
// flush the writes
(void) ohci_readl (ohci, &ohci->regs->control);
msleep(temp);
- temp = roothub_a (ohci);
- if (!(temp & RH_A_NPS)) {
- /* power down each port */
- for (temp = 0; temp < ohci->num_ports; temp++)
- ohci_writel (ohci, RH_PS_LSDA,
- &ohci->regs->roothub.portstatus [temp]);
- }
- // flush those writes
- (void) ohci_readl (ohci, &ohci->regs->control);
+
memset (ohci->hcca, 0, sizeof (struct ohci_hcca));
/* 2msec timelimit here means no irqs/preempt */
@@ -826,17 +818,8 @@
if ((temp = ohci_run (ohci)) < 0) {
ohci_err (ohci, "can't restart, %d\n", temp);
return temp;
- } else {
- /* here we "know" root ports should always stay powered,
- * and that if we try to turn them back on the root hub
- * will respond to CSC processing.
- */
- i = ohci->num_ports;
- while (i--)
- ohci_writel (ohci, RH_PS_PSS,
- &ohci->regs->roothub.portstatus [i]);
- ohci_dbg (ohci, "restart complete\n");
}
+ ohci_dbg(ohci, "restart complete\n");
return 0;
}
#endif
diff --git a/drivers/usb/host/ohci-pci.c b/drivers/usb/host/ohci-pci.c
index ca62cb5..15013f4 100644
--- a/drivers/usb/host/ohci-pci.c
+++ b/drivers/usb/host/ohci-pci.c
@@ -202,6 +202,42 @@
return ret;
}
+#if defined(CONFIG_USB_PERSIST) && (defined(CONFIG_USB_EHCI_HCD) || \
+ defined(CONFIG_USB_EHCI_HCD_MODULE))
+
+/* Following a power loss, we must prepare to regain control of the ports
+ * we used to own. This means turning on the port power before ehci-hcd
+ * tries to switch ownership.
+ *
+ * This isn't a 100% perfect solution. On most systems the OHCI controllers
+ * lie at lower PCI addresses than the EHCI controller, so they will be
+ * discovered (and hence resumed) first. But there is no guarantee things
+ * will always work this way. If the EHCI controller is resumed first and
+ * the OHCI ports are unpowered, then the handover will fail.
+ */
+static void prepare_for_handover(struct usb_hcd *hcd)
+{
+ struct ohci_hcd *ohci = hcd_to_ohci(hcd);
+ int port;
+
+ /* Here we "know" root ports should always stay powered */
+ ohci_dbg(ohci, "powerup ports\n");
+ for (port = 0; port < ohci->num_ports; port++)
+ ohci_writel(ohci, RH_PS_PPS,
+ &ohci->regs->roothub.portstatus[port]);
+
+ /* Flush those writes */
+ ohci_readl(ohci, &ohci->regs->control);
+ msleep(20);
+}
+
+#else
+
+static inline void prepare_for_handover(struct usb_hcd *hcd)
+{ }
+
+#endif /* CONFIG_USB_PERSIST etc. */
+
#ifdef CONFIG_PM
static int ohci_pci_suspend (struct usb_hcd *hcd, pm_message_t message)
@@ -241,7 +277,10 @@
static int ohci_pci_resume (struct usb_hcd *hcd)
{
set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
- usb_hcd_resume_root_hub(hcd);
+
+ /* FIXME: we should try to detect loss of VBUS power here */
+ prepare_for_handover(hcd);
+
return 0;
}