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authorJavier Martinez Canillas <javier@dowhile0.org>2013-01-07 01:35:20 +0000
committerTom Rini <trini@ti.com>2013-01-10 15:09:24 -0700
commit7de0fe1ac330399afc1873e11061668a93cf4fb9 (patch)
tree1dbd487b9b511aec938cb52c1b4accf62b051f75 /README
parent94bcfe524cab9574f799bd2b7df9c7de2b81465a (diff)
serial/ns16550: add an option to avoid hanging on broken platforms
Some platforms (e.g. IGEPv2 board) has a broken ns16550 UART that does not set the TEMT bit when the transmitter is empty in SPL. This makes U-Boot to hang while waiting for TEMT to be set. Add a new option to avoid this: CONFIG_SYS_NS16550_BROKEN_TEMT 16550 UART set the Transmitter Empty (TEMT) Bit when all output has finished and the transmitter is totally empty. U-Boot waits for this bit to be set to initialize the serial console. On some broken platforms this bit is not set in SPL making U-Boot to hang while waiting for TEMT. Define this option to avoid it. Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Diffstat (limited to 'README')
-rw-r--r--README8
1 files changed, 8 insertions, 0 deletions
diff --git a/README b/README
index 653ef6aa4a..98dbe98c2e 100644
--- a/README
+++ b/README
@@ -616,6 +616,14 @@ The following options need to be configured:
boot loader that has already initialized the UART. Define this
variable to flush the UART at init time.
+ CONFIG_SYS_NS16550_BROKEN_TEMT
+
+ 16550 UART set the Transmitter Empty (TEMT) Bit when all output
+ has finished and the transmitter is totally empty. U-Boot waits
+ for this bit to be set to initialize the serial console. On some
+ broken platforms this bit is not set in SPL making U-Boot to
+ hang while waiting for TEMT. Define this option to avoid it.
+
- Console Interface:
Depending on board, define exactly one serial port