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authorÁlvaro Fernández Rojas <noltari@gmail.com>2019-12-23 17:25:19 +0100
committerÁlvaro Fernández Rojas <noltari@gmail.com>2019-12-24 18:49:49 +0100
commitc2308a7e4adbb2acc8ff149f91d1ca46801c135e (patch)
treeffc720dc7c05c331d6569fc3c2f0772fb375e419 /target/linux/brcm2708/patches-4.19/950-0035-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch
parent67dcc43f3a22dc3a7ac07a7065971b426feeb043 (diff)
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brcm2708: update to latest patches from RPi Foundation
Also removes reverted patches. Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Diffstat (limited to 'target/linux/brcm2708/patches-4.19/950-0035-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch')
-rw-r--r--target/linux/brcm2708/patches-4.19/950-0035-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch27
1 files changed, 27 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0035-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch b/target/linux/brcm2708/patches-4.19/950-0035-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch
new file mode 100644
index 0000000000..30ac2a883c
--- /dev/null
+++ b/target/linux/brcm2708/patches-4.19/950-0035-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch
@@ -0,0 +1,27 @@
+From 76627df3e5f0513118dac20710766f97fc5ca32d Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+Date: Fri, 29 Sep 2017 10:32:19 +0100
+Subject: [PATCH] amba_pl011: Insert mb() for correct FIFO handling
+
+The pl011 register accessor functions use the _relaxed versions of the
+standard readl() and writel() functions, meaning that there are no
+automatic memory barriers. When polling a FIFO status register to check
+for fullness, it is necessary to ensure that any outstanding writes have
+completed; otherwise the flags are effectively stale, making it possible
+that the next write is to a full FIFO.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+---
+ drivers/tty/serial/amba-pl011.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/drivers/tty/serial/amba-pl011.c
++++ b/drivers/tty/serial/amba-pl011.c
+@@ -1383,6 +1383,7 @@ static bool pl011_tx_char(struct uart_am
+ return false; /* unable to transmit character */
+
+ pl011_write(c, uap, REG_DR);
++ mb();
+ uap->port.icount.tx++;
+
+ return true;