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:
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On 03/25/2013 11:02 PM, Manfred Huber wrote:
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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);
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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.
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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