Am 28.03.2013 09:45, schrieb Andreas Bießmann:
Dear Manfred Huber,
On 03/28/2013 07:06 AM, Manfred Huber wrote:
On 2013-03-27 14:37, Andreas Bießmann wrote:
<snip>
On 03/25/2013 11:02 PM, Manfred Huber wrote:
<snip>
+ serial_out(UART_LCR_DLAB, &com_port->lcr);
+ serial_out(baud_divisor & 0xff, &com_port->dll);
+ serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
+ serial_out(UART_LCRVAL, &com_port->lcr);
+ serial_out(0, &com_port->mdr1);
<snip>
I wonder which use-case requires UART flushing in u-boot context before
initializing the UART for u-boot correctly. Can someone explain this to
me? Shouldn't we always start here from the very beginning and setup
UART as configured?
Beagleboard has several ways to boot (NAND, SD/MMC, UART, ...). For the
boot mode with UART, Beagleboard configures the UART and ends with a non
empty transmitter. In a booting sequence where UART is before NAND,
SD/MMC or wherever SPL starts from, we have not a clean UART.
<snip>
It's not critical. So I guess it's not needed for this release.
Well, if there are boards in the field that will not boot with the next
release I think it is critical.
We do have some omap3 (omap35xx and am37xx) based boards here. I can
recall a situation where some few boards did not boot from sd-card while
serial debug cable was attached (AFAIR this was not the case when
booting from NAND). The root cause was never investigated, so maybe we
suffered exactly this bug.
Can you test this boars with my patch?
Best regards
Andreas Bießmann
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