EHCI: keep track of ports being resumed and indicate in hub_status_data
This patch (as1537) adds a bit-array to ehci-hcd for keeping track of
which ports are undergoing a resume transition. If any of the bits
are set when ehci_hub_status_data() is called, the routine will return
a nonzero value even if no ports have any status changes pending.
This will allow usbcore to handle races between root-hub suspend and
port wakeup.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Sarah Sharp <sarah.a.sharp@linux.intel.com>
CC: Chen Peter-B29397 <B29397@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 256fbd4..38fe076 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -223,15 +223,10 @@
* 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 +549,12 @@
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 +563,11 @@
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
@@ -846,6 +842,7 @@
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 +861,7 @@
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 +882,10 @@
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 +920,7 @@
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);