On Tue, Apr 12, 2016 at 10:21 AM, Michel Dänzer <[email protected]> wrote: > On 11.04.2016 23:34, Oded Gabbay wrote: >> This patch adds a new field, called "endian_format", to >> "struct pipe_resource". The new field is of type "enum pipe_endian" and >> can receive one of two values: >> - PIPE_ENDIAN_LITTLE >> - PIPE_ENDIAN_NATIVE >> >> PIPE_ENDIAN_NATIVE is initialized to either PIPE_ENDIAN_LITTLE or >> PIPE_ENDIAN_BIG during build time. >> >> This field is needed to provide information to the H/W drivers about the >> endianess current state or desired state of the resource. In other words, >> for resources that are the source of the operation, this field indicates >> the resource's current memory layout endianess (big or little endian). >> For resources that are the destination of the operation, this field >> indicates the resource's desired memory layout endianess. >> >> This field is mandatory because of how mesa works. When we get into the >> H/W driver functions, the driver *ususally* doesn't know if it is doing a >> CPU->GPU, a GPU->CPU, a CPU->CPU or a GPU->GPU operation, as this >> information is "hidden" by the fact we go through common code >> paths (state tracker layer). > > That shouldn't matter if the formats are defined completely and their > usage is consistent across the board. Sounds like either or both of > those conditions aren't completely true yet. I agree with Roland that > this should be addressed fundamentally rather than adding more hacks on top.
I disagree with your statement. The formats are defined correctly, it's just that the software rendering drivers can use the automatically generated functions in u_format_table.c to handle all the endianess issues, while H/W drivers won't do it. So H/W drivers need additional hint. In any case, I have no intentions what-so-ever to re-work the entire mesa/gallium formats system again. Oded > > > -- > Earthling Michel Dänzer | http://www.amd.com > Libre software enthusiast | Mesa and X developer _______________________________________________ mesa-dev mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/mesa-dev
