This is a note to let you know that I've just added the patch titled
xHCI: keep track of ports being resumed and indicate in hub_status_data
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xhci-keep-track-of-ports-being-resumed-and-indicate-in-hub_status_data.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From f370b9968a220a3d79d870dd7dee674cc0ff3d10 Mon Sep 17 00:00:00 2001
From: Andiry Xu <[email protected]>
Date: Sat, 14 Apr 2012 02:54:30 +0800
Subject: xHCI: keep track of ports being resumed and indicate in hub_status_data
From: Andiry Xu <[email protected]>
commit f370b9968a220a3d79d870dd7dee674cc0ff3d10 upstream.
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 <[email protected]>
Signed-off-by: Sarah Sharp <[email protected]>
Cc: Alan Stern <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/usb/host/xhci-hub.c | 22 ++++++++++++----------
drivers/usb/host/xhci-ring.c | 1 +
drivers/usb/host/xhci.c | 12 ++++++++++--
drivers/usb/host/xhci.h | 2 ++
4 files changed, 25 insertions(+), 12 deletions(-)
--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -558,6 +558,7 @@ int xhci_hub_control(struct usb_hcd *hcd
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
/* 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;
@@ -885,15 +891,11 @@ 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) {
- spin_unlock_irqrestore(&xhci->lock, flags);
- xhci_dbg(xhci, "suspend failed because "
- "port %d is resuming\n",
- port_index + 1);
- return -EBUSY;
- }
+ if (bus_state->resuming_ports) {
+ spin_unlock_irqrestore(&xhci->lock, flags);
+ xhci_dbg(xhci, "suspend failed because "
+ "a port is resuming\n");
+ return -EBUSY;
}
}
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1377,6 +1377,7 @@ static void handle_port_status(struct xh
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 */
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -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
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -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)
Patches currently in stable-queue which might be from [email protected] are
queue-3.4/xhci-keep-track-of-ports-being-resumed-and-indicate-in-hub_status_data.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
