From c76e4de05c23fea3d6ad6df63876a9397dd7c85a Mon Sep 17 00:00:00 2001 From: Elric Fu Date: Wed, 27 Jun 2012 16:30:57 +0800 Subject: [PATCH] xHCI: add cmd_ring_state commit c181bc5b5d5c79b71203cd10cef97f802fb6f9c1 upstream. 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. Signed-off-by: Elric Fu Signed-off-by: Sarah Sharp Tested-by: Miroslav Sabljic Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci-ring.c | 3 +++ drivers/usb/host/xhci.c | 5 ++++- drivers/usb/host/xhci.h | 4 ++++ 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c index 152daca4822b..402777915774 100644 --- a/drivers/usb/host/xhci-ring.c +++ b/drivers/usb/host/xhci-ring.c @@ -311,6 +311,9 @@ static 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 c39ab20077aa..73deef90e831 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -104,8 +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; + xhci->cmd_ring_state = CMD_RING_STATE_STOPPED; + } return ret; } @@ -390,6 +392,7 @@ 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 21482dff7232..876862b38649 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1252,6 +1252,10 @@ 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; -- 2.39.5