2013/9/12 Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>:
> It is not mine, I just fixed an existent code which applies a wrong errata
> to 1074K.
> Errata fix did exist before me.
Are there any reasons why you cannot quote an internal note about this
errata which would give a better idea of what this code is about?
Sorry but the diff really does not help understand what is happening
without a proper explanation of why this is required. At first glance
it would like some revisions of the CPU are affected by some D$ bug?
> - Leonid.
> On 09/12/2013 08:12 AM, Paul Burton wrote:
>> Agreed, my point is not about your code but your commit message. If I'm
>> reading a commit which works around CPU errata I should not have to go and
>> ask the hardware engineers or even read an errata document in order to know
>> what you're doing. Your commit message should explain the errata, its
>> effects and how your patch works around the problem.
>> On 12/09/13 16:05, Florian Fainelli wrote:
>>> 2013/9/12 Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>:
>>>> Treat it as is.
>>>> It is a dirty laundry of HW engineers and you may need to communicate
>>>> with them or read Errata docs on CPU.
>>>> If it is about a way how it is written - ask Steven, initially it was in
>>>> mainland probe code but he think it should be a separate function. I just
>>>> corrected him, pointing that erratas on 74K and 1074K are different. But
>>>> because he insist on having the same CPU_74K for both, so...
>>> If you take a look at another CPU company such as ARM, they provide
>>> lengthy explanations for their various Erratas:
>>> config PJ4B_ERRATA_4742
>>> bool "PJ4B Errata 4742: IDLE Wake Up Commands can Cause the
>>> CPU Core to Cease Operation"
>>> depends on CPU_PJ4B && MACH_ARMADA_370
>>> default y
>>> When coming out of either a Wait for Interrupt (WFI) or a Wait
>>> Event (WFE) IDLE states, a specific timing sensitivity exists
>>> the retiring WFI/WFE instructions and the newly issued
>>> instructions. This sensitivity can result in a CPU hang
>>> The software must insert either a Data Synchronization Barrier
>>> or Data Memory Barrier (DMB) command immediately after the
>>> I really think that you should aim for the same level of information
>>> so that people know whether this is relevant for their platform,
>>> whether they have the ECO applied etc...