[RFC] ttm merge ttm_backend & ttm_tt

[Jerome Glisse]

On Tue, Nov 1, 2011 at 9:29 PM, Konrad Rzeszutek Wilk
<konrad.wilk at oracle.com> wrote:
> On Tue, Nov 01, 2011 at 09:11:37PM -0400, Jerome Glisse wrote:
>> Hi,
>>
>> So attached is patch serie (sorry for that i am away of my normal mail
>> config) which ultimately merge ttm_backend & ttm_tt it allows to get
>> rid of data duplication btw the two, especialy btw ttm_tt and driver
>> specific backend. So net result is less 300lines of code accross ttm
>> and driver.
>>
>> Konrad given some of the upstream nouveau change, your patchserie
>> conflict and would lead to revert some nouveau fixes. I believe the
>> intention is to get the ttm-dma code into 3.3 (3.2 seems late but
>> dunno). If 3.3 is the aim than i will rebase your patch on top of this
>
> Yup. 3.3.

So basicly the issue is that nouveau now abuse the ttm dma_address
array to store the result of the pci map page, issue is then to either
code your ttm page code or pci unmap when unmapping. This can be
worked around, i have half a rebase patch already. But i believe if
ttm_backend & ttm_tt are merge and with proper page callback helper,
nouveau could be more easily adapted.

Anyway both approach can be taken either you patch on top or bottom.
As it's somewhat different issue.

Cheers,
Jerome