DRM_TEGRA_SUBMIT_BUF_WRITE_RELOC

[Dmitry Osipenko]

09.09.2020 11:10, Mikko Perttunen пишет:
> On 9/9/20 2:45 AM, Dmitry Osipenko wrote:
>> 05.09.2020 13:34, Mikko Perttunen пишет:
>> ...
>>> +/* Submission */
>>> +
>>> +/** Patch address of the specified mapping in the submitted gather. */
>>> +#define DRM_TEGRA_SUBMIT_BUF_WRITE_RELOC        (1<<0)
>>
>> Shouldn't the kernel driver be aware about what relocations need to be
>> patched? Could you please explain the purpose of this flag?
>>
> 
> Sure, the kernel knows if it returned the IOVA to the user or not, so we
> could remove this flag and determine it implicitly. I don't think there
> is much harm in it though; if we have the flag an application can decide
> to ignore the iova field and just pass WRITE_RELOC always, and it's not
> really any extra code on kernel side.

Sounds like there is no real practical use for this flag other than for
testing purposes, correct?