xHCI: add cmd_ring_state
Elric Fu [Wed, 27 Jun 2012 08:30:57 +0000 (16:30 +0800)]
Adding cmd_ring_state for command ring. It helps to verify
the current command ring state for controlling the command
ring operations.

This patch should be backported to kernels as old as 3.0.  The commit
7ed603ecf8b68ab81f4c83097d3063d43ec73bb8 "xhci: Add an assertion to
check for virt_dev=0 bug." papers over the NULL pointer dereference that
I now believe is related to a timed out Set Address command.  This (and
the four patches that follow it) contain the real fix that also allows
VIA USB 3.0 hubs to consistently re-enumerate during the plug/unplug
stress tests.

Change-Id: I50976948d2d81a73d7019b20139e93d1a84e38e5
Signed-off-by: Elric Fu <elricfu1@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Miroslav Sabljic <miroslav.sabljic@avl.com>
Cc: stable@vger.kernel.org
Signed-off-by: Ajay Gupta <ajayg@nvidia.com>
Reviewed-on: http://git-master/r/192885
(cherry picked from commit e3a84306998accbf075697d88792cd6c1eabe435)

Signed-off-by: JC Kuo <jckuo@nvidia.com>
Change-Id: I8f5b60cfa1d78d5c8f6790027cd2b1847b3fa699
Reviewed-on: http://git-master/r/194690
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Ajay Gupta <ajayg@nvidia.com>
Reviewed-by: Ashutosh Jha <ajha@nvidia.com>

drivers/usb/host/xhci-ring.c
drivers/usb/host/xhci.c
drivers/usb/host/xhci.h

index 203ba31..dc9e6e9 100644 (file)
@@ -280,6 +280,9 @@ static inline int room_on_ring(struct xhci_hcd *xhci, struct xhci_ring *ring,
 /* Ring the host controller doorbell after placing a command on the ring */
 void xhci_ring_cmd_db(struct xhci_hcd *xhci)
 {
+       if (!(xhci->cmd_ring_state & CMD_RING_STATE_RUNNING))
+               return;
+
        xhci_dbg(xhci, "// Ding dong!\n");
        xhci_writel(xhci, DB_VALUE_HOST, &xhci->dba->doorbell[0]);
        /* Flush PCI posted writes */
index f5dc94f..ab6b889 100644 (file)
@@ -104,9 +104,10 @@ int xhci_halt(struct xhci_hcd *xhci)
 
        ret = handshake(xhci, &xhci->op_regs->status,
                        STS_HALT, STS_HALT, XHCI_MAX_HALT_USEC);
-       if (!ret)
+       if (!ret) {
                xhci->xhc_state |= XHCI_STATE_HALTED;
-       else
+               xhci->cmd_ring_state = CMD_RING_STATE_STOPPED;
+       } else
                xhci_warn(xhci, "Host not halted after %u microseconds.\n",
                                XHCI_MAX_HALT_USEC);
        return ret;
@@ -485,6 +486,7 @@ static int xhci_run_finished(struct xhci_hcd *xhci)
                return -ENODEV;
        }
        xhci->shared_hcd->state = HC_STATE_RUNNING;
+       xhci->cmd_ring_state = CMD_RING_STATE_RUNNING;
 
        if (xhci->quirks & XHCI_NEC_HOST)
                xhci_ring_cmd_db(xhci);
index 19ae30f..3904589 100644 (file)
@@ -1417,6 +1417,10 @@ struct xhci_hcd {
        /* data structures */
        struct xhci_device_context_array *dcbaa;
        struct xhci_ring        *cmd_ring;
+       unsigned int            cmd_ring_state;
+#define CMD_RING_STATE_RUNNING         (1 << 0)
+#define CMD_RING_STATE_ABORTED         (1 << 1)
+#define CMD_RING_STATE_STOPPED         (1 << 2)
        unsigned int            cmd_ring_reserved_trbs;
        struct xhci_ring        *event_ring;
        struct xhci_erst        erst;