From 688915b11aa7f8b92d12a2e4672d71e3626a0e6a Mon Sep 17 00:00:00 2001
From: Mathias Nyman <mathias.nyman@linux.intel.com>
Date: Thu, 23 Jul 2020 17:45:29 +0300
Subject: [PATCH] xhci: dbgcap: remove dbc dependency on dbctty specific flag
Git-commit: 688915b11aa7f8b92d12a2e4672d71e3626a0e6a
References: jsc#SLE-14911
Patch-mainline: v5.9-rc1

dbc should not be aware of, or use any dbctty specific variables.
currenly dbc driver reads the port->registered flag to see if the
callbacks should be called.

Only makes these decisions based on dbc internal state instead.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200723144530.9992-27-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/host/xhci-dbgcap.c | 16 ++++++++++++----
 drivers/usb/host/xhci-dbgtty.c |  5 +++++
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/host/xhci-dbgcap.c b/drivers/usb/host/xhci-dbgcap.c
index 47090bceae21..c57178db7994 100644
--- a/drivers/usb/host/xhci-dbgcap.c
+++ b/drivers/usb/host/xhci-dbgcap.c
@@ -630,14 +630,22 @@ static void xhci_dbc_stop(struct xhci_dbc *dbc)
 {
 	int ret;
 	unsigned long		flags;
-	struct dbc_port		*port = &dbc->port;
 
 	WARN_ON(!dbc);
 
-	cancel_delayed_work_sync(&dbc->event_work);
+	switch (dbc->state) {
+	case DS_DISABLED:
+		return;
+	case DS_CONFIGURED:
+	case DS_STALLED:
+		if (dbc->driver->disconnect)
+			dbc->driver->disconnect(dbc);
+		break;
+	default:
+		break;
+	}
 
-	if (port->registered && dbc->driver->disconnect)
-		dbc->driver->disconnect(dbc);
+	cancel_delayed_work_sync(&dbc->event_work);
 
 	spin_lock_irqsave(&dbc->lock, flags);
 	ret = xhci_do_dbc_stop(dbc);
diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c
index 3231cec74a7a..3b306a22da47 100644
--- a/drivers/usb/host/xhci-dbgtty.c
+++ b/drivers/usb/host/xhci-dbgtty.c
@@ -399,6 +399,9 @@ int xhci_dbc_tty_register_device(struct xhci_dbc *dbc)
 	struct device		*tty_dev;
 	struct dbc_port		*port = &dbc->port;
 
+	if (port->registered)
+		return -EBUSY;
+
 	xhci_dbc_tty_init_port(dbc, port);
 	tty_dev = tty_port_register_device(&port->port,
 					   dbc_tty_driver, 0, NULL);
@@ -445,6 +448,8 @@ void xhci_dbc_tty_unregister_device(struct xhci_dbc *dbc)
 {
 	struct dbc_port		*port = &dbc->port;
 
+	if (!port->registered)
+		return;
 	tty_unregister_device(dbc_tty_driver, 0);
 	xhci_dbc_tty_exit_port(port);
 	port->registered = false;
-- 
2.26.2