All of lore.kernel.org
 help / color / mirror / Atom feed
* [U-Boot] [PATCH] OMAP3: pandora: fix booting without serial attached
@ 2009-11-11 20:56 Grazvydas Ignotas
  2009-11-11 21:14 ` Tom
  0 siblings, 1 reply; 4+ messages in thread
From: Grazvydas Ignotas @ 2009-11-11 20:56 UTC (permalink / raw)
  To: u-boot

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.

Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
---
 board/pandora/pandora.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/board/pandora/pandora.h b/board/pandora/pandora.h
index 5bfa0f9..f1e1db9 100644
--- a/board/pandora/pandora.h
+++ b/board/pandora/pandora.h
@@ -219,7 +219,7 @@ 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*/\
+	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*/\
-- 
1.5.4.3

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [U-Boot] [PATCH] OMAP3: pandora: fix booting without serial attached
  2009-11-11 20:56 [U-Boot] [PATCH] OMAP3: pandora: fix booting without serial attached Grazvydas Ignotas
@ 2009-11-11 21:14 ` Tom
  2009-11-11 21:34   ` Grazvydas Ignotas
  0 siblings, 1 reply; 4+ messages in thread
From: Tom @ 2009-11-11 21:14 UTC (permalink / raw)
  To: u-boot

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.
> 
> Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
> ---
>  board/pandora/pandora.h |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/board/pandora/pandora.h b/board/pandora/pandora.h
> index 5bfa0f9..f1e1db9 100644
> --- a/board/pandora/pandora.h
> +++ b/board/pandora/pandora.h
> @@ -219,7 +219,7 @@ 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*/\
> +	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*/\

Will this change disable normal u-boot serial?
 From the config file

/*
  * select serial console configuration
  */
#define CONFIG_CONS_INDEX		3
#define CONFIG_SYS_NS16550_COM3		OMAP34XX_UART3
#define CONFIG_SERIAL3			3

It looks like it will.

This must be as a non default config option.

Tom

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [U-Boot] [PATCH] OMAP3: pandora: fix booting without serial attached
  2009-11-11 21:14 ` Tom
@ 2009-11-11 21:34   ` Grazvydas Ignotas
  2009-11-11 23:43     ` Tom
  0 siblings, 1 reply; 4+ messages in thread
From: Grazvydas Ignotas @ 2009-11-11 21:34 UTC (permalink / raw)
  To: u-boot

On Wed, Nov 11, 2009 at 11:14 PM, Tom <Tom.Rix@windriver.com> wrote:
> 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.
>>
>> Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
>> ---
>> ?board/pandora/pandora.h | ? ?2 +-
>> ?1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/board/pandora/pandora.h b/board/pandora/pandora.h
>> index 5bfa0f9..f1e1db9 100644
>> --- a/board/pandora/pandora.h
>> +++ b/board/pandora/pandora.h
>> @@ -219,7 +219,7 @@ 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*/\
>> + ? ? ? 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*/\
>
> Will this change disable normal u-boot serial?

No it won't, it only enables weak internal pullup resistor in OMAP,
which won't prevent the UART from working, only pull it up when
nothing is driving the pin (i.e. cable not conneted).

> From the config file
>
> /*
> ?* select serial console configuration
> ?*/
> #define CONFIG_CONS_INDEX ? ? ? ? ? ? ? 3
> #define CONFIG_SYS_NS16550_COM3 ? ? ? ? OMAP34XX_UART3
> #define CONFIG_SERIAL3 ? ? ? ? ? ? ? ? ?3
>
> It looks like it will.
>
> This must be as a non default config option.
>
> Tom

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [U-Boot] [PATCH] OMAP3: pandora: fix booting without serial attached
  2009-11-11 21:34   ` Grazvydas Ignotas
@ 2009-11-11 23:43     ` Tom
  0 siblings, 0 replies; 4+ messages in thread
From: Tom @ 2009-11-11 23:43 UTC (permalink / raw)
  To: u-boot

Grazvydas Ignotas wrote:
> On Wed, Nov 11, 2009 at 11:14 PM, Tom <Tom.Rix@windriver.com> wrote:
>> 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.
>>>
>>> Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
>>> ---
>>>  board/pandora/pandora.h |    2 +-
>>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>>
>>> diff --git a/board/pandora/pandora.h b/board/pandora/pandora.h
>>> index 5bfa0f9..f1e1db9 100644
>>> --- a/board/pandora/pandora.h
>>> +++ b/board/pandora/pandora.h
>>> @@ -219,7 +219,7 @@ 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*/\
>>> +       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*/\
>> Will this change disable normal u-boot serial?
> 
> No it won't, it only enables weak internal pullup resistor in OMAP,
> which won't prevent the UART from working, only pull it up when
> nothing is driving the pin (i.e. cable not conneted).

Good.
Please add this comment to the commit log.
Please also add a similar comment to the code.

The mux code is cyptic, documenting helps.
Tom

> 
>> From the config file
>>
>> /*
>>  * select serial console configuration
>>  */
>> #define CONFIG_CONS_INDEX               3
>> #define CONFIG_SYS_NS16550_COM3         OMAP34XX_UART3
>> #define CONFIG_SERIAL3                  3
>>
>> It looks like it will.
>>
>> This must be as a non default config option.
>>
>> Tom

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2009-11-11 23:43 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-11-11 20:56 [U-Boot] [PATCH] OMAP3: pandora: fix booting without serial attached Grazvydas Ignotas
2009-11-11 21:14 ` Tom
2009-11-11 21:34   ` Grazvydas Ignotas
2009-11-11 23:43     ` Tom

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.