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author | Álvaro Fernández Rojas <noltari@gmail.com> | 2020-02-29 09:25:20 +0100 |
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committer | Álvaro Fernández Rojas <noltari@gmail.com> | 2020-02-29 12:50:51 +0100 |
commit | a1383655cfaa71609d6236ae0fcf3b6047462b98 (patch) | |
tree | c6f123859e0dfcfaa6c1063eda26f27e208d3cac /target/linux/bcm27xx/patches-5.4/950-0033-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch | |
parent | a8aa974a9dfb4cba484dc4c1e4207fd9ec803410 (diff) | |
download | upstream-a1383655cfaa71609d6236ae0fcf3b6047462b98.tar.gz upstream-a1383655cfaa71609d6236ae0fcf3b6047462b98.tar.bz2 upstream-a1383655cfaa71609d6236ae0fcf3b6047462b98.zip |
bcm27xx: add linux 5.4 support
Tested on bcm2710 (Raspberry Pi 3B).
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0033-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch')
-rw-r--r-- | target/linux/bcm27xx/patches-5.4/950-0033-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0033-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch b/target/linux/bcm27xx/patches-5.4/950-0033-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch new file mode 100644 index 0000000000..f545ab1db0 --- /dev/null +++ b/target/linux/bcm27xx/patches-5.4/950-0033-amba_pl011-Insert-mb-for-correct-FIFO-handling.patch @@ -0,0 +1,27 @@ +From 37e06c9ed7219cf6cf08a0463f7e2b5b2c51f3e6 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; |