On 10/19/2018 05:25 AM, Simon Glass wrote:
On 9 August 2018 at 13:04, Simon Goldschmidt simon.k.r.goldschmidt@gmail.com wrote:
If _debug_uart_putc() is called before _debug_uart_init(), the ns16550 debug uart driver hangs in a tight loop waiting for the tx FIFO to get empty.
As this can happen via a printf sneaking in before the port calls debug_uart_init(), let's rather ignore characters before the debug uart is initialized.
This is done by reading the baudrate divisor and aborting if is zero.
Tested on socfpga_cyclone5_socrates.
Signed-off-by: Simon Goldschmidt simon.k.r.goldschmidt@gmail.com
v2:
- this patch is new in v2 of the series. It replaces the printf/debug
change in reset_manager_gen5.c from v1
drivers/serial/ns16550.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
We cannot use global_data before it is set up, so I think this is the best solution.
Acked-by: Simon Glass sjg@chromium.org
So there's no GD available when using debug uart ? Hum.
btw. Does the NS16550_read_baud_divisor() need to be called within the while loop ?