Re: [Xenomai] IMX kernel 3.0.35_4.1.0 + adeos-ipipe-3.0.43-mx6q-1.18-14 -> very slow boot

[Thierry Bultel <tbultel@free.fr>]

Le 12/11/2014 16:55, Gilles Chanteperdrix a écrit :
> On Wed, Nov 12, 2014 at 04:44:24PM +0100, Thierry Bultel wrote:
>> Le 12/11/2014 16:29, Gilles Chanteperdrix a écrit :
>>> On Wed, Nov 12, 2014 at 04:20:50PM +0100, Thierry Bultel wrote:
>>>> Le 12/11/2014 15:30, Gilles Chanteperdrix a écrit :
>>>>> On Wed, Nov 12, 2014 at 03:27:11PM +0100, Thierry Bultel wrote:
>>>>>> Le 12/11/2014 14:34, Gilles Chanteperdrix a écrit :
>>>>>>> On Wed, Nov 12, 2014 at 02:17:11PM +0100, Thierry Bultel wrote:
>>>>>>>> Le 11/11/2014 21:03, Gilles Chanteperdrix a écrit :
>>>>>>>>> On Tue, Nov 11, 2014 at 08:57:34PM +0100, Thierry Bultel wrote:
>>>>>>>>>> Le 10/11/2014 13:36, Gilles Chanteperdrix a écrit :
>>>>>>>>>>> You can use printascii in the timer interrupt acknowledge routine to
>>>>>>>>>>> print a character every HZ ticks, this will give bad latency, but
>>>>>>>>>>> should work.
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> For unknown reason, the kernel gets stuck after
>>>>>>>>>> "console [tty0] enabled, bootconsole disabled" if I use printascii
>>>>>>>>>> in do_local_timer().
>>>>>>>>>> earlyprintk seems broken as well.
>>>>>>>>>
>>>>>>>>> Without doing this, does earlyprintk work?
>>>>>>>>
>>>>>>>> No it does not. In fact, this kernel is strange with early debug.
>>>>>>>> Namely, even without earlyprintk, when it comes to disable the
>>>>>>>> bootconsole to use the normal one, it uses then re-prints everything
>>>>>>>> was printed before, making think that it has restarted from the
>>>>>>>> beginning.
>>>>>>>>
>>>>>>>> I confirm that calling printascii in do_local_timer() leads to a
>>>>>>>> kernel panic. Same thing if I use __ipipe_serial_debug instead.
>>>>>>>> I have used a counter (one per cpu) to start logging after 30000
>>>>>>>> ticks and it crashes after that delay.
>>>>>>>
>>>>>>> Having looked at the sources, I do not find a debug-macro.S for
>>>>>>> imx6. So, I doubt printascii can work at all. Maybe a first step is
>>>>>>> to implement this missing support.
>>>>>>
>>>>>> I think that the implementation is in arch/arm/plat-mxc/include
>>>>>> /mach/debug-macro.S
>>>>>
>>>>> And the debug UART you are using is UART2 ?
>>>>>
>>>> Yes,
>>>> and I have found out why the logs before the console switch were
>>>> displayed twice. This is because the BSP directly calls
>>>>
>>>> early_console_setup(UART2_BASE_ADDR, uart_clk);
>>>>
>>>> removing it does not make earlyprintk or printascii work better,
>>>> unfortunately.
>>>
>>> Do you get the "Uncompressing kernel..." message on the console?
>>>
>> This is all what I get when adding earlyprintk=serial,ttymxc1,115200
>> to the bootargs:
>>
>>
>> Uncompressing Linux... done, booting the kernel.
>> Linux version 3.0.43_4.1.0 (localuser@thierry-desktop) (gcc version
>> 4.7.3 (Buildroot 2014.02-rc3-g7ebc513) ) #20 SMP PREEMPT Wed Nov 12
>> 16:10:51 CET 2014
>> CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7), cr=10c53c7d
>> CPU: VIPT nonaliasing data cache, VIPT aliasing instruction cache
>> Machine: Freescale i.MX 6Quad VAB-820 Board
>> bootconsole [earlycon0] enabled
>> Memory policy: ECC disabled, Data cache writealloc
>> CPU identified as i.MX6Q, silicon rev 1.2
>>
>> <nothing after>
>
> Your problem seems to be that a static mapping for the UART2
> registers is missing: printascii only works so long as the MMU is
> not enabled.
>
> Please try the following patch:
> diff --git a/arch/arm/mach-mx6/mm.c b/arch/arm/mach-mx6/mm.c
> index ad66a94..789d265 100644
> --- a/arch/arm/mach-mx6/mm.c
> +++ b/arch/arm/mach-mx6/mm.c
> @@ -56,6 +56,11 @@ static struct map_desc mx6_io_desc[] __initdata = {
>   	.pfn = __phys_to_pfn(ARM_PERIPHBASE),
>   	.length = ARM_PERIPHBASE_SIZE,
>   	.type = MT_DEVICE},
> +	{
> +	.virtual = IMX_IO_ADDRESS(MX6Q_UART2_BASE_ADDR),
> +	.pfn = __phys_to_pfn(MX6Q_UART2_BASE_ADDR),
> +	.length = 4096,
> +	.type = MT_DEVICE},
>   };
>
>   static void mx6_set_cpu_type(void)
>
>
Many thanks Gilles, that solves both my call to printascii and 
earlyprintk in bootargs.
I keep trying to reproduce the freeze

Thierry