Brijesh Singh brijeshkumar.singh at amd.com
Wed Oct 21 09:22:24 PDT 2015

On 10/21/2015 05:01 AM, Andre Przywara wrote:
> Hi,
> On 21/10/15 10:35, Borislav Petkov wrote:
>> On Wed, Oct 21, 2015 at 09:55:43AM +0800, Hanjun Guo wrote:
>>> So I think the meaning of those error register is the same, but the way
>>> of handle it may different from SoCs, for single bit error:
>>>  - SoC may trigger a interrupt;
>>>  - SoC may just keep silent so we need to scan the registers using poll
>>>    mechanism.
>>> For Double bit error:
>>>   - SoC may also keep silent
>>>   - Trigger a interrupt
>>>   - Trigger a SEI (system error)
>>> Any suggestion to cover those cases?
>> Well, I guess we can implement all those and have them configurable
>> in the sense that a single driver loads, it has all functionality and
>> dependent on the vendor detection, it does only what the vendor wants
>> like trigger an interrupt or remain silent or ...
> I guess the firmware (running in EL3) will take precedence over this
> driver anyway, so we could just optimistically implement all errors, as
> the driver will just never see errors that are handled in firmware (?)
> In case of a critical error for instance I expect the firmware to never
> return to EL1.
>> Btw, in talking about this with Andre last night, he had the suggestion
>> that this functionality is also in other implementations besides A57 so
>> maybe the driver should be called arm_cortex_edac...
> Yeah, so looking at the A-72 and the A-53 TRM I see those registers to
> be there as well. The A-72 and the A-57 versions look identical to me,
> the A-53 version is only slightly different, but apparently still
> compatible.
> So I'd suggest to let this driver load on detecting all three MIDRs.
> Should later revisions of any of those parts change the register
> meaning, we could add a blacklist or specific MIDR detection.
> But let's just not assume the worst in the first place ;-)
Ok. Will make it generic cortex_arm64_edac. Will check MIDR and call appropriate CPUMERRSR_EL1 and L2MERRSR_EL1. Since I don't have A53 and A72 hence my testing will be limited to Cortex A57.
> Cheers,
> Andre.
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