[PATCH 1/4] xHCI: add cmd_ring_state

[Elric Fu <elricfu1@xxxxxxxxx>]

Adding cmd_ring_state for command ring. It helps to verify
the current command ring state for controlling the command
ring operations.

Signed-off-by: Elric Fu <elricfu1@xxxxxxxxx>
---
 drivers/usb/host/xhci-ring.c |    3 +++
 drivers/usb/host/xhci.c      |    6 ++++--
 drivers/usb/host/xhci.h      |    4 ++++
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 23b4aef..54948ad 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -272,6 +272,9 @@ 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 */
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index a979cd0..f498350 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -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;
@@ -484,6 +485,7 @@ 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);
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index de3d6e3..107b4d8 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -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;
-- 
1.7.9.1

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