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EHCI: keep track of ports being resumed and indicate in hub_status_data

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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>
This commit is contained in:
Alan Stern
2012-04-03 15:24:30 -04:00
committed by Greg Kroah-Hartman
parent 879d38e6bc
commit a448e4dc25
4 changed files with 23 additions and 15 deletions
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31
drivers/usb/host/ehci-hub.c
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@@ -223,15 +223,10 @@ 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 +549,12 @@ 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 +563,11 @@ 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
@@ -846,6 +842,7 @@ 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 +861,7 @@ 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 +882,10 @@ 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 +920,7 @@ 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);