CHROMIUM: usb: ehci: Only sleep for post-resume handover if devices use persist

[cascardo/linux.git] / drivers / usb / host / ehci-hub.c

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 256fbd4..4adfe77 100644 (file)
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -42,6 +42,13 @@ static int ehci_hub_control(
        u16             wLength
 );
 
+
+static int persist_enabled_on_companion(struct usb_device *udev, void *unused)
+{
+       return !udev->maxchild && udev->persist_enabled &&
+               udev->bus->root_hub->speed < USB_SPEED_HIGH;
+}
+
 /* After a power loss, ports that were owned by the companion must be
  * reset so that the companion can still own them.
  */
@@ -56,6 +63,16 @@ static void ehci_handover_companion_ports(struct ehci_hcd *ehci)
        if (!ehci->owned_ports)
                return;
 
+       /*
+        * USB 1.1 devices are mostly HIDs, which don't need to persist across
+        * suspends. If we ensure that none of our companion's devices have
+        * persist_enabled (by looking through all USB 1.1 buses in the system),
+        * we can skip this and avoid slowing resume down. Devices without
+        * persist will just get reenumerated shortly after resume anyway.
+        */
+       if (!usb_for_each_dev(NULL, persist_enabled_on_companion))
+               return;
+
        /* Give the connections some time to appear */
        msleep(20);
 
@@ -223,15 +240,10 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
         * remote wakeup, we must fail the suspend.
         */
        if (hcd->self.root_hub->do_remote_wakeup) {
-               port = HCS_N_PORTS(ehci->hcs_params);
-               while (port--) {
-                       if (ehci->reset_done[port] != 0) {
-                               spin_unlock_irq(&ehci->lock);
-                               ehci_dbg(ehci, "suspend failed because "
-                                               "port %d is resuming\n",
-                                               port + 1);
-                               return -EBUSY;
-                       }
+               if (ehci->resuming_ports) {
+                       spin_unlock_irq(&ehci->lock);
+                       ehci_dbg(ehci, "suspend failed because a port is resuming\n");
+                       return -EBUSY;
                }
        }
 
@@ -554,16 +566,12 @@ static int
 ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
 {
        struct ehci_hcd *ehci = hcd_to_ehci (hcd);
-       u32             temp, status = 0;
+       u32             temp, status;
        u32             mask;
        int             ports, i, retval = 1;
        unsigned long   flags;
        u32             ppcd = 0;
 
-       /* if !USB_SUSPEND, root hub timers won't get shut down ... */
-       if (ehci->rh_state != EHCI_RH_RUNNING)
-               return 0;
-
        /* init status to no-changes */
        buf [0] = 0;
        ports = HCS_N_PORTS (ehci->hcs_params);
@@ -572,6 +580,11 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
                retval++;
        }
 
+       /* Inform the core about resumes-in-progress by returning
+        * a non-zero value even if there are no status changes.
+        */
+       status = ehci->resuming_ports;
+
        /* Some boards (mostly VIA?) report bogus overcurrent indications,
         * causing massive log spam unless we completely ignore them.  It
         * may be relevant that VIA VT8235 controllers, where PORT_POWER is
@@ -616,7 +629,11 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
                        status = STS_PCD;
                }
        }
-       /* FIXME autosuspend idle root hubs */
+
+       /* If a resume is in progress, make sure it can finish */
+       if (ehci->resuming_ports)
+               mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(25));
+
        spin_unlock_irqrestore (&ehci->lock, flags);
        return status ? retval : 0;
 }
@@ -846,6 +863,7 @@ static int ehci_hub_control (
                                ehci_writel(ehci,
                                        temp & ~(PORT_RWC_BITS | PORT_RESUME),
                                        status_reg);
+                               clear_bit(wIndex, &ehci->resuming_ports);
                                retval = handshake(ehci, status_reg,
                                           PORT_RESUME, 0, 2000 /* 2msec */);
                                if (retval != 0) {
@@ -864,6 +882,7 @@ static int ehci_hub_control (
                                        ehci->reset_done[wIndex])) {
                        status |= USB_PORT_STAT_C_RESET << 16;
                        ehci->reset_done [wIndex] = 0;
+                       clear_bit(wIndex, &ehci->resuming_ports);
 
                        /* force reset to complete */
                        ehci_writel(ehci, temp & ~(PORT_RWC_BITS | PORT_RESET),
@@ -884,8 +903,10 @@ static int ehci_hub_control (
                                        ehci_readl(ehci, status_reg));
                }
 
-               if (!(temp & (PORT_RESUME|PORT_RESET)))
+               if (!(temp & (PORT_RESUME|PORT_RESET))) {
                        ehci->reset_done[wIndex] = 0;
+                       clear_bit(wIndex, &ehci->resuming_ports);
+               }
 
                /* transfer dedicated ports to the companion hc */
                if ((temp & PORT_CONNECT) &&
@@ -920,6 +941,7 @@ static int ehci_hub_control (
                        status |= USB_PORT_STAT_SUSPEND;
                } else if (test_bit(wIndex, &ehci->suspended_ports)) {
                        clear_bit(wIndex, &ehci->suspended_ports);
+                       clear_bit(wIndex, &ehci->resuming_ports);
                        ehci->reset_done[wIndex] = 0;
                        if (temp & PORT_PE)
                                set_bit(wIndex, &ehci->port_c_suspend);
@@ -965,6 +987,12 @@ static int ehci_hub_control (
                if (!wIndex || wIndex > ports)
                        goto error;
                wIndex--;
+
+               /* test if the port is configured to be ignored */
+               if (ehci->port_used_bitmap &&
+                               !(ehci->port_used_bitmap & (1 << wIndex)))
+                       goto error_exit;
+
                temp = ehci_readl(ehci, status_reg);
                if (temp & PORT_OWNER)
                        break;