diff options
author | Álvaro Fernández Rojas <noltari@gmail.com> | 2019-07-09 20:32:28 +0200 |
---|---|---|
committer | Álvaro Fernández Rojas <noltari@gmail.com> | 2019-07-14 12:44:14 +0200 |
commit | 42954857190b9df16d9d873ecc7f6cc38e013e44 (patch) | |
tree | 98c588f629ff534d458eb0884782ea99672d7634 /target/linux/brcm2708/patches-4.19/950-0036-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch | |
parent | f1875e902d0afb7d9b9e5285b4fd8da7f6c5e30a (diff) | |
download | upstream-42954857190b9df16d9d873ecc7f6cc38e013e44.tar.gz upstream-42954857190b9df16d9d873ecc7f6cc38e013e44.tar.bz2 upstream-42954857190b9df16d9d873ecc7f6cc38e013e44.zip |
brcm2708: add linux 4.19 support
Boot tested on Raspberry Pi B+ (BCM2708) and Raspberry Pi 2 (BCM2709)
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Diffstat (limited to 'target/linux/brcm2708/patches-4.19/950-0036-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch')
-rw-r--r-- | target/linux/brcm2708/patches-4.19/950-0036-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/target/linux/brcm2708/patches-4.19/950-0036-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch b/target/linux/brcm2708/patches-4.19/950-0036-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch new file mode 100644 index 0000000000..d98a85985d --- /dev/null +++ b/target/linux/brcm2708/patches-4.19/950-0036-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch @@ -0,0 +1,27 @@ +From 0ebd5e2c627c3c41a1081f6c1b7e7caa13e5b12e Mon Sep 17 00:00:00 2001 +From: Phil Elwell <phil@raspberrypi.org> +Date: Fri, 29 Sep 2017 10:32:19 +0100 +Subject: [PATCH 036/703] 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 +@@ -1385,6 +1385,7 @@ 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; |