[meta-freescale] Should all T4240 errata be applied to T1040?

[Bob Cochran]

On 09/19/2014 06:04 AM, zhenhua.luo at freescale.com wrote:
> Hi Bob,
>
> Thanks for the great finding.
>
> Defining the CONFIG_FMAN_T4240 for T1 is inaccurate and potentially dangerous for the correct function. The manual explicitly states for TNTSKS that exceeding the max supported values is not permitted, but it doesn't actually state that the reset value is the maximum permissible value.
>
> As for the correct way to define things, we probably need to share integrations across common SoCs per, e.g., Table A-5 in the T1040 DPAA RM to make SW match our docs properly. A configuration "T4240" is likely a bad one anyway if we should name it effectively "FMAN_V3H_384KiB" vs. "FMAN_V3H_512KiB" for B4860 rev 2.  So it is good to change "FMAN_V3L" for T1 to match the documentation and part behavior.
>
> Also the correct way is to stop configuring such things at compile time to avoid separate kernel build for every FMan revision.


Thank you for the quick reply Zhenhua.  Your proposed solution makes 
sense to me.

I'm seeing other registers that have their values set to FMAN_v3H rather 
than FMAN_v3L values, and I'm trying to track them down in the source to 
see whether they are being incorrectly set (or maybe the doc is wrong?).

Perhaps I'll send you a list of suspicious register settings in the next 
few days.

I continue to investigate the DPAA to hopefully resolve CPU hangs & oops 
during network loading.

Bob








>
>
> Best Regards,
>
> Zhenhua
>
>> -----Original Message-----
>> From: meta-freescale-bounces at yoctoproject.org [mailto:meta-freescale-
>> bounces at yoctoproject.org] On Behalf Of Bob Cochran
>> Sent: Thursday, September 18, 2014 11:44 AM
>> To: meta-freescale at yoctoproject.org
>> Subject: [meta-freescale] Should all T4240 errata be applied to T1040?
>>
>> I find that during initialization of my T1040rdb-64b using the kernel built with
>> meta-fsl-ppc master, the FMBM_CFG2.TNTASKS field (total number of BMI
>> tasks) is being overwritten to 0x7b (the reset value is documented as 0x3b in
>> the T1040 reference manual).
>>
>> I believe this is being overwritten due to sharing the errata definitions with the
>> T4240, but this particular erratum may not apply to the T1040 and may cause
>> undesirable side effects.
>>
>> The T4240 uses DPAA FMAN_v3H, and the T1040 uses DPAA FMAN_v3L.
>>
>>
>> Here is my understanding of how this erratum (A005127) is being applied to the
>> T1040:
>>
>> 1) t1040_64bit_smp_defconfig defines CONFIG_FMAN_T4240
>>
>> 2) By defining CONFIG_FMAN_T4240,
>> drivers/net/ethernet/freescale/fman/ncsw_config.mk adds
>> -I$(FMAN)/inc/integrations/T4240 to EXTRA_CFLAGS.
>>
>> 3) dpaa_integration_ext.h is included throughout the fman source files from
>> drivers/net/ethernet/freescale/fman/inc/integrations/T4240
>>
>> 4) This defines FM_WRONG_RESET_VALUES_ERRATA_FMAN_A005127, but it is
>> my understanding that this erratum does not apply to the T1040.
>>
>> 5) This results in FMBM_CFG2.TNTASKS being overwritten with a value
>> approximately twice its default value, and my concern is that the FMAN_V3L
>> does not have the resources to support this many tasks.
>>
>>
>>
>> In general, I'm also wondering whether the other errata in the integration file is
>> appropriate for the T1040 and whether the FMAN_v3L devices should have
>> their own integration tree.
>>
>>
>>
>>
>>
>> --
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