3.4-stable review patch. If anyone has any objections, please let me know.
------------------ 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) -- 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
