[U-Boot] [PATCH v2] OMAP3: pandora: fix booting without serial attached

Tom Tom.Rix at windriver.com
Thu Nov 12 14:39:24 CET 2009


Grazvydas Ignotas wrote:
> When the board is booted without serial cable attached (which
> is how most of them will be used) UART RX is left floating and
> sometimes picks noise, which interrupts countdown and enters
> U-Boot prompt instead of booting the kernel.
> 
> Fix this by setting up internal pullup on UART RX pin. This
> does not prevent serial from working as the internal pullup
> is weak.
> 
> Signed-off-by: Grazvydas Ignotas <notasas at gmail.com>

Ack.
Thanks.

> ---
> It would be nice for this to go in as a fix for 2009.11,
> else users without serial cable won't be able to boot it.
> 

Wolfgang,
Can this fix be included in 2009.11 ?

Tom


>  board/pandora/pandora.h |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/board/pandora/pandora.h b/board/pandora/pandora.h
> index 5bfa0f9..f0ad16b 100644
> --- a/board/pandora/pandora.h
> +++ b/board/pandora/pandora.h
> @@ -219,7 +219,8 @@ const omap3_sysinfo sysinfo = {
>  	MUX_VAL(CP(UART2_RX),		(IEN  | PTD | EN  | M4)) /*GPIO_147,*/\
>  								 /*UART2_RX*/\
>   /*Serial Interface (Peripheral boot, Linux console, on AV connector)*/\
> -	MUX_VAL(CP(UART3_RX_IRRX),	(IEN  | PTD | DIS | M0)) /*UART3_RX*/\
> + /*RX pulled up to avoid noise when nothing is connected to serial port*/\
> +	MUX_VAL(CP(UART3_RX_IRRX),	(IEN  | PTU | EN  | M0)) /*UART3_RX*/\
>  	MUX_VAL(CP(UART3_TX_IRTX),	(IDIS | PTD | DIS | M0)) /*UART3_TX*/\
>   /*LEDs (Controlled by OMAP)*/\
>  	MUX_VAL(CP(MMC1_DAT6),		(IDIS | PTD | DIS | M4)) /*GPIO_128*/\



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