Hi Marek,
On Thu, 10 Jul 2014 12:14:35 +0200 Marek Vasut marex@denx.de wrote:
+static void uniphier_serial_putc(struct uniphier_serial *port, const char c) +{
- if (c == '\n')
uniphier_serial_putc(port, '\r');- while (!(readb(&port->lsr) & UART_LSR_THRE))
;I think in this function, you can avoid such completely unbounded loop.
[...]
Why? Could you give me more detailed explanation?
In case the LSR_THRE bit would never get cleared, this loop would keep spinning forever. On the other hand, if there was some kind of a timeout, U-Boot would be able to continue doing at least something when exiting this loop by timing out. Though you're right that something would most likely have gone really bonkers if this LSR_THRE never got cleared.
I guess you mentioned the case where the flow control with CTS/RTS results in the dead lock.
I am not sure if we need to be so careful.
Is there any other UART driver using timeout check?
(What would U-Boot continue to do in case console cannot display the error message?)
Best Regards Masahiro Masahiro