[RFC] Host1x/TegraDRM UAPI

[Dmitry Osipenko]

25.06.2020 02:18, Dmitry Osipenko пишет:
> 23.06.2020 15:09, Mikko Perttunen пишет:
>> struct drm_tegra_channel_submit {
>>         __u32 channel_id;
>>         __u32 flags;
>>
>>         /**
>>          * [in] Timeout in microseconds after which the kernel may
>>          *   consider the job to have hung and may reap it and
>>          *   fast-forward its syncpoint increments.
>>          *
>>          *   The value may be capped by the kernel.
>>          */
>>         __u32 timeout;
>>
>>         __u32 num_syncpt_incrs;
>>         __u32 num_relocations;
>>         __u32 num_commands;
>>
>>         __u64 syncpt_incrs;
>>         __u64 relocations;
>>         __u64 commands;
> 
> Do we really need to retain the multi-gather support? The code-bloat
> (both userspace and kernel driver) is very significant just for
> preparing and patching of the multi-buffer cmdstreams.
> 
> If userspace runs out of a free space within the pushbuffer, then it
> should simply reallocate a larger pushbuffer.
> 
> I'm suggesting that we should have a single gather per-job, any objections?
> 

Oh, I just recalled that the later Host1x versions do not allow  to
switch class from gather! Let me think a bit more about it..