(CC: Ben, John) On Thu, Mar 27, 2025 at 02:03:21PM -0400, M Henning wrote: > On Thu, Mar 27, 2025 at 9:51 AM Danilo Krummrich <d...@kernel.org> wrote: > > > > On Fri, Mar 21, 2025 at 06:06:34PM -0400, M Henning wrote: > > > On Thu, Mar 20, 2025 at 2:18 PM Danilo Krummrich <d...@kernel.org> wrote: > > > > On Wed, Mar 12, 2025 at 05:36:14PM -0400, Mel Henning wrote: > > > > > + __u32 width_align_pixels; > > > > > + __u32 height_align_pixels; > > > > > + __u32 pixel_squares_by_aliquots; > > > > > + __u32 aliquot_total; > > > > > + __u32 zcull_region_byte_multiplier; > > > > > + __u32 zcull_region_header_size; > > > > > + __u32 zcull_subregion_header_size; > > > > > + __u32 subregion_count; > > > > > + __u32 subregion_width_align_pixels; > > > > > + __u32 subregion_height_align_pixels; > > > > > + > > > > > + __u32 ctxsw_size; > > > > > + __u32 ctxsw_align; > > > > > +}; > > > > > > > > What if this ever changes between hardware revisions or firmware > > > > versions? > > > > > > There was some previous discussion of that here: > > > https://gitlab.freedesktop.org/mesa/mesa/-/issues/12596#note_2796853 > > > > > > From what I can tell, this structure hasn't really changed since > > > FERMI_C (circa 2011), so I'm not too worried about it changing on us > > > too quickly. When it does change, we have the option of appending more > > > members to this struct in the usual way, or if the change is more > > > fundamental we can return an error from this ioctl and add a new > > > interface. Userspace needs to handle an error from this ioctl > > > gracefully anyway since whether it works or not depends on the gpu > > > generation and what firmware is loaded right now. > > > > We could also define it as > > > > struct drm_nouveau_get_zcull_info { > > __u32 version; > > __u32 _pad; > > > > union { > > struct drm_nouveau_get_zcull_info_v1 info; > > } > > } > > > > just to be safe. > > We can do that, although I don't see any other drm drivers using a > similar pattern anywhere.
I think it's a bit cleaner than adding new members, leave existing ones unset or add a new IOCTL in the worst case. Maybe the NVIDIA folks can give us some hint on whether this is expected to change at some point?
