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 879d38e6bc36d73b0ac40ec9b0d839fda9fa8b1a "USB: fix race
between root-hub suspend and remote wakeup".
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: stable@vger.kernel.org
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 36641a7..5910048 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -152,7 +152,7 @@
{
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 @@
* 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