From: Felipe Balbi <balbi@ti.com>
Date: Wed, 23 Apr 2014 14:58:27 +0000 (-0500)
Subject: Revert "serial: omap: unlock the port lock"
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=6bf789672ee8387fda08af1deeffd12126e60659;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

Revert "serial: omap: unlock the port lock"

This reverts commit 0324a821029e1f54e7a7f8fed48693cfce42dc0e.

That commit tried to fix a deadlock problem when using
hci_ldisc, but it turns out the bug was in hci_ldsic
all along where it was calling ->write() from within
->write_wakeup() callback.

The problem is that ->write_wakeup() was called with
port lock held and ->write() tried to grab the same
port lock.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 08b6b9419f0d..837f6c1c8e7a 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -398,11 +398,8 @@ static void transmit_chars(struct uart_omap_port *up, unsigned int lsr)
 			break;
 	} while (--count > 0);
 
-	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) {
-		spin_unlock(&up->port.lock);
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
 		uart_write_wakeup(&up->port);
-		spin_lock(&up->port.lock);
-	}
 
 	if (uart_circ_empty(xmit))
 		serial_omap_stop_tx(&up->port);