From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Thu, 13 Feb 2020 18:31:16 +0000 (-0800)
Subject: 4.19-stable patches
X-Git-Tag: v4.4.214~7
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f8f85b4b9eaa60bf6d736623c450b4c1f2108f42;p=thirdparty%2Fkernel%2Fstable-queue.git

4.19-stable patches

added patches:
	serial-uartps-move-the-spinlock-after-the-read-of-the-tx-empty.patch
---

diff --git a/queue-4.19/serial-uartps-move-the-spinlock-after-the-read-of-the-tx-empty.patch b/queue-4.19/serial-uartps-move-the-spinlock-after-the-read-of-the-tx-empty.patch
new file mode 100644
index 00000000000..07f7070e42d
--- /dev/null
+++ b/queue-4.19/serial-uartps-move-the-spinlock-after-the-read-of-the-tx-empty.patch
@@ -0,0 +1,40 @@
+From 107475685abfdee504bb0ef4824f15797f6d2d4d Mon Sep 17 00:00:00 2001
+From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
+Date: Fri, 24 May 2019 14:41:28 +0530
+Subject: serial: uartps: Move the spinlock after the read of the tx empty
+
+From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
+
+commit 107475685abfdee504bb0ef4824f15797f6d2d4d upstream.
+
+Currently we are doing a read of the status register.
+Move the spinlock after that as the reads need not be spinlock
+protected. This patch prevents relaxing the cpu with spinlock held.
+
+Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
+Cc: Pavel Machek <pavel@denx.de>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ drivers/tty/serial/xilinx_uartps.c |    3 +--
+ 1 file changed, 1 insertion(+), 2 deletions(-)
+
+--- a/drivers/tty/serial/xilinx_uartps.c
++++ b/drivers/tty/serial/xilinx_uartps.c
+@@ -686,8 +686,6 @@ static void cdns_uart_set_termios(struct
+ 	unsigned int ctrl_reg, mode_reg, val;
+ 	int err;
+ 
+-	spin_lock_irqsave(&port->lock, flags);
+-
+ 	/* Wait for the transmit FIFO to empty before making changes */
+ 	if (!(readl(port->membase + CDNS_UART_CR) &
+ 				CDNS_UART_CR_TX_DIS)) {
+@@ -699,6 +697,7 @@ static void cdns_uart_set_termios(struct
+ 			return;
+ 		}
+ 	}
++	spin_lock_irqsave(&port->lock, flags);
+ 
+ 	/* Disable the TX and RX to set baud rate */
+ 	ctrl_reg = readl(port->membase + CDNS_UART_CR);
diff --git a/queue-4.19/series b/queue-4.19/series
index a3d39e11777..8fc9ee4cf12 100644
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -50,3 +50,4 @@ libertas-make-lbs_ibss_join_existing-return-error-co.patch
 scsi-megaraid_sas-do-not-initiate-ocr-if-controller-is-not-in-ready-state.patch
 x86-stackframe-move-encode_frame_pointer-to-asm-frame.h.patch
 x86-stackframe-x86-ftrace-add-pt_regs-frame-annotations.patch
+serial-uartps-move-the-spinlock-after-the-read-of-the-tx-empty.patch