Commit f370b996 authored by Andiry Xu's avatar Andiry Xu Committed by Sarah Sharp

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

This commit adds a bit-array to xhci bus_state for keeping track of
which ports are undergoing a resume transition. If any of the bits
are set when xhci_hub_status_data() is called, the routine will return
a non-zero value even if no ports have any status changes pending.
This will allow usbcore to handle races between root-hub suspend and
port wakeup.

This patch should be backported to kernels as old as 3.4, that contain
the commit 879d38e6 "USB: fix race
between root-hub suspend and remote wakeup".
Signed-off-by: default avatarAndiry Xu <andiry.xu@amd.com>
Signed-off-by: default avatarSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org
parent 32445605
......@@ -558,6 +558,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
xhci_dbg(xhci, "Resume USB2 port %d\n",
wIndex + 1);
bus_state->resume_done[wIndex] = 0;
clear_bit(wIndex, &bus_state->resuming_ports);
xhci_set_link_state(xhci, port_array, wIndex,
XDEV_U0);
xhci_dbg(xhci, "set port %d resume\n",
......@@ -845,7 +846,12 @@ int xhci_hub_status_data(struct usb_hcd *hcd, char *buf)
/* Initial status is no changes */
retval = (max_ports + 8) / 8;
memset(buf, 0, retval);
status = 0;
/*
* Inform the usbcore about resume-in-progress by returning
* a non-zero value even if there are no status changes.
*/
status = bus_state->resuming_ports;
mask = PORT_CSC | PORT_PEC | PORT_OCC | PORT_PLC | PORT_WRC;
......@@ -885,17 +891,13 @@ int xhci_bus_suspend(struct usb_hcd *hcd)
spin_lock_irqsave(&xhci->lock, flags);
if (hcd->self.root_hub->do_remote_wakeup) {
port_index = max_ports;
while (port_index--) {
if (bus_state->resume_done[port_index] != 0) {
if (bus_state->resuming_ports) {
spin_unlock_irqrestore(&xhci->lock, flags);
xhci_dbg(xhci, "suspend failed because "
"port %d is resuming\n",
port_index + 1);
"a port is resuming\n");
return -EBUSY;
}
}
}
port_index = max_ports;
bus_state->bus_suspended = 0;
......
......@@ -1377,6 +1377,7 @@ static void handle_port_status(struct xhci_hcd *xhci,
xhci_dbg(xhci, "resume HS port %d\n", port_id);
bus_state->resume_done[faked_port_index] = jiffies +
msecs_to_jiffies(20);
set_bit(faked_port_index, &bus_state->resuming_ports);
mod_timer(&hcd->rh_timer,
bus_state->resume_done[faked_port_index]);
/* Do the rest in GetPortStatus */
......
......@@ -152,7 +152,7 @@ int xhci_reset(struct xhci_hcd *xhci)
{
u32 command;
u32 state;
int ret;
int ret, i;
state = xhci_readl(xhci, &xhci->op_regs->status);
if ((state & STS_HALT) == 0) {
......@@ -175,7 +175,15 @@ int xhci_reset(struct xhci_hcd *xhci)
* xHCI cannot write to any doorbells or operational registers other
* than status until the "Controller Not Ready" flag is cleared.
*/
return handshake(xhci, &xhci->op_regs->status, STS_CNR, 0, 250 * 1000);
ret = handshake(xhci, &xhci->op_regs->status, STS_CNR, 0, 250 * 1000);
for (i = 0; i < 2; ++i) {
xhci->bus_state[i].port_c_suspend = 0;
xhci->bus_state[i].suspended_ports = 0;
xhci->bus_state[i].resuming_ports = 0;
}
return ret;
}
#ifdef CONFIG_PCI
......
......@@ -1362,6 +1362,8 @@ struct xhci_bus_state {
u32 suspended_ports;
u32 port_remote_wakeup;
unsigned long resume_done[USB_MAXCHILDREN];
/* which ports have started to resume */
unsigned long resuming_ports;
};
static inline unsigned int hcd_index(struct usb_hcd *hcd)
......
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