brcm2708: rename target to bcm27xx

This change makes the names of Broadcom targets consistent by using
the common notation based on SoC/CPU ID (which is used internally
anyway), bcmXXXX instead of brcmXXXX.
This is even used for target TITLE in make menuconfig already,
only the short target name used brcm so far.

Despite, since subtargets range from bcm2708 to bcm2711, it seems
appropriate to use bcm27xx instead of bcm2708 (again, as already done
for BOARDNAME).

This also renames the packages brcm2708-userland and brcm2708-gpu-fw.

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>
Acked-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 42 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-4.19/950-0807-tty-amba-pl011-Avoid-rare-write-when-full-error.patch b/target/linux/bcm27xx/patches-4.19/950-0807-tty-amba-pl011-Avoid-rare-write-when-full-error.patch
new file mode 100644
index 0000000000..8deb882a98
--- /dev/null
+++ b/target/linux/bcm27xx/patches-4.19/950-0807-tty-amba-pl011-Avoid-rare-write-when-full-error.patch
@@ -0,0 +1,42 @@
+From 8ef5143f743a4e922fdf0029f81452d3d7003daf Mon Sep 17 00:00:00 2001
+From: Phil Elwell <phil@raspberrypi.org>
+Date: Wed, 29 Jan 2020 09:35:19 +0000
+Subject: [PATCH] tty: amba-pl011: Avoid rare write-when-full error
+
+Under some circumstances on BCM283x processors data loss can be
+observed - a single byte missing from the TX output stream. These bytes
+are always the last byte of a batch of 8 written from pl011_tx_chars
+when from_irq is true, meaning that the FIFO full flag is not checked
+before writing.
+
+The transmit optimisation relies on the FIFO being half-empty when the
+TX interrupt is raised. Instrumenting the driver further showed that
+the failure case correlated with the TX FIFO full flag being set at the
+point where the last byte was written to the data register, which
+explains the data loss but not how the FIFO appeared to be prematurely
+full. A possible explanation is that a FIFO write was in flight at the
+time the interrupt was raised, but as yet there is no hypothesis as to
+how this might occur.
+
+In the absence of a clear understanding of the failure mechanism, avoid
+the problem by checking the FIFO levels before writing the last byte of
+the group, which will have minimal performance impact.
+
+Signed-off-by: Phil Elwell <phil@raspberrypi.org>
+---
+ drivers/tty/serial/amba-pl011.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+--- a/drivers/tty/serial/amba-pl011.c
++++ b/drivers/tty/serial/amba-pl011.c
+@@ -1444,6 +1444,10 @@ static bool pl011_tx_chars(struct uart_a
+ 		if (likely(from_irq) && count-- == 0)
+ 			break;
+ 
++		if (likely(from_irq) && count == 0 &&
++		    pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
++			break;
++
+ 		if (!pl011_tx_char(uap, xmit->buf[xmit->tail], from_irq))
+ 			break;
+