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From: Manfred Huber <man.huber@arcor.de>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH 1/1 v2] omap3_beagle: Enabling UART3 first allows the Transmitter to be empty
Date: Wed, 27 Mar 2013 05:50:17 +0100	[thread overview]
Message-ID: <51527A89.6070406@arcor.de> (raw)
In-Reply-To: <5150C987.1040802@arcor.de>

Please test the Patch. It is very simple on a Beagleboard. I guess you
have flashed the actual SPL and u-boot and Beagleboard boots correctly.
Now press and hold 'User' button and connect power. SPL should hang.
You can see some symbols on the console from the ROM code.

Install the Patch, compile it and flash the NAND. Beagleboard still
boots correctly. Now press and hold 'User' button again and Beagleboard
should also boot correctly. The Patch works.

I suspect the IGEP board has the same bug. If so, the Patch should work
on this board too and we don't need CONFIG_SYS_NS16550_BROKEN_TEMT
anymore.

If you don't want a patch for this bug please let me know. I will not
bother you again.

Best regards,
Manfred


On 2013-03-25 23:02, Manfred Huber wrote:
> From: Manfred Huber
>
> Due to a Bug in the ROM code of some OMAP3 devices, the TEMT bit is not
> set if UART3 is configured before (only THRE is set). Reason is the
> disabling of UART3 even though the Transmitter is not empty. Enabling
> UART3 allows the Transmitter to be empty.
>
> Signed-off-by: Manfred Huber <man.huber@arcor.de>
> ---
>   drivers/serial/ns16550.c |   12 ++++++++++--
>   1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
> index b2da8b3..24ff84f 100644
> --- a/drivers/serial/ns16550.c
> +++ b/drivers/serial/ns16550.c
> @@ -36,10 +36,18 @@
>
>   void NS16550_init(NS16550_t com_port, int baud_divisor)
>   {
> -#if (!defined(CONFIG_SYS_NS16550_BROKEN_TEMT))
> +#if (defined(CONFIG_SPL_BUILD) && defined(CONFIG_OMAP34XX))
> +    if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
> == UART_LSR_THRE) {
> +        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);
> +    }
> +#endif
> +
>       while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
>           ;
> -#endif
>
>       serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
>   #if (defined(CONFIG_OMAP) && !defined(CONFIG_OMAP3_ZOOM2)) || \
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot

  reply	other threads:[~2013-03-27  4:50 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-27 13:09 [U-Boot] Beagleboard: SPL hangs on serial init man.huber at arcor.de
2013-03-16 13:13 ` Manfred Huber
2013-03-19 14:49   ` Tom Rini
2013-03-19 23:52     ` Manfred Huber
2013-03-20  0:05     ` Javier Martinez Canillas
2013-03-20  1:27       ` Tom Rini
2013-03-20 23:09         ` Manfred Huber
2013-03-21 21:08           ` Javier Martinez Canillas
2013-03-23 10:11             ` Manfred Huber
2013-03-21 19:03       ` [U-Boot] [PATCH] omap3_beagle: Enable CONFIG_SYS_NS16550_BROKEN_TEMT Manfred Huber
2013-03-21 21:28         ` Javier Martinez Canillas
2013-03-21 22:21         ` Tom Rini
2013-03-21 22:28           ` Scott Wood
2013-03-25 22:02       ` [U-Boot] [PATCH 1/1 v2] omap3_beagle: Enabling UART3 first allows the Transmitter to be empty Manfred Huber
2013-03-27  4:50         ` Manfred Huber [this message]
2013-03-27  9:29           ` Javier Martinez Canillas
2013-03-27 13:57             ` Tom Rini
2013-03-28  5:55             ` Manfred Huber
2013-03-29  8:19             ` Manfred Huber
2013-03-28 15:21           ` Tom Rini
2013-03-27 13:37         ` Andreas Bießmann
2013-03-27 17:22           ` Javier Martinez Canillas
2013-03-28  6:06           ` Manfred Huber
2013-03-28  8:45             ` Andreas Bießmann
2013-03-28  9:11               ` Javier Martinez Canillas
2013-03-28  9:50                 ` Andreas Bießmann
2013-03-28 15:21                   ` Tom Rini
2013-03-29  8:33               ` Manfred Huber
2013-03-29  9:20       ` [U-Boot] [PATCH 1/1 v3] " Manfred Huber
2013-03-29  9:43         ` Albert ARIBAUD
2013-03-29 12:34           ` Tom Rini
2013-03-29 12:42       ` [U-Boot] [PATCH 1/1 v4] omap3_beagle: Flush UART3 xmit on enable if TEMT is broken Manfred Huber
2013-03-29 12:52       ` [U-Boot] [PATCH 1/1 v5] " Manfred Huber
2013-04-02  7:46         ` Javier Martinez Canillas
2013-04-02  8:59         ` Andreas Bießmann
2013-04-08 16:56         ` [U-Boot] [U-Boot, 1/1, " Tom Rini
2013-04-10 22:12       ` [U-Boot] [PATCH v1 1/1] omap3: Display MHz instead of mHz on the console Manfred Huber

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