[U-Boot] [PATCH 0/6] board: ti: am43xx: Enable hardware leveling

[Keerthy]

On 15/04/19 7:43 AM, keerthy wrote:
> 
> 
> On 4/15/2019 6:35 AM, Tom Rini wrote:
>> On Mon, Apr 15, 2019 at 06:19:31AM +0530, keerthy wrote:
>>>
>>>
>>> On 4/13/2019 6:32 PM, Tom Rini wrote:
>>>> On Fri, Apr 12, 2019 at 12:08:14PM +0530, Keerthy wrote:
>>>>
>>>>> The series adds the support for hardware leveling. This needs the
>>>>> kernel to be patched with hardware leveling support and the
>>>>> kernel support is already in linux-next:
>>>>>
>>>>> https://patchwork.kernel.org/project/linux-omap/list/?series=100273
>>>>>
>>>>> Match recommended values from EMIF Tools app note:
>>>>> http://www.ti.com/lit/an/sprac70/sprac70.pdf
>>>>
>>>> What happens if you boot an old kernel with this series applied?  I'm a
>>>> bit worried about applying something that breaks existing kernels,
>>>> thanks!
>>>
>>> Hi Tom,
>>>
>>> Deep Sleep 0 feature will fail as the corresponding hardware leveling
>>> patches will not be present.
>>
>> So to be clear, some new functionality will not work, but there is no
>> functional regression?
> 
> Okay i got your concern. Deep sleep 0 is currently working with software 
> leveling that will stop working with this patch series(hardware 
> leveling) applied on older kernels. EMIF tools application note 
> recommends hardware leveling over what existed previously.
> 
> Hence i posted this series. Older kernels with this patch series Deep 
> sleep 0 feature will regress.

Tom,

We need hardware leveling as per EMIF document. So older kernels at best 
can backport the patches here:

https://patchwork.kernel.org/patch/10882123/
https://patchwork.kernel.org/patch/10882127/

I do not see any other way to enable hardware leveling.

Tero/Dave,

Any concerns?

Regards,
Keerthy
> 
>>
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