Hey Krzysztof, Krzysztof Kozlowski wrote: > On 05/24/2016 06:05 PM, Tobias Jakobi wrote: >> Hello Krzysztof, >> >> >> Krzysztof Kozlowski wrote: >>> On 05/24/2016 03:49 PM, Tobias Jakobi wrote: >>>> Hello Krzysztof, >>>> >>>> are you sure that these are the only differences. Because AFAIK there >>>> are quite a few more: >>>> - DMA submission of commands >>>> - blend mode / rounding >>>> - solid fill >>>> - YCrCb support >>>> - and probably more >>>> >>>> One would need to add least split the command list parser into a v3 and >>>> v41 version to accomodate for the differences. In fact userspace/libdrm >>>> would need to know which hw type it currently uses, but you currently >>>> always return 4.1 in the corresponding ioctl. >>> >>> Eh, so probably my patch does not cover fully the support for v3 G2D. I >>> looked mostly at the differences between v3 and v4 in the s5p-g2d driver >>> itself. However you are right that this might be not sufficient because >>> exynos-g2d moved forward and is different than s5p-g2d. >>> >>>> Krzysztof Kozlowski wrote: >>>>> The non-DRM s5p-g2d driver supports two versions of G2D: v3.0 on >>>>> S5Pv210 and v4.x on Exynos 4x12 (or newer). The driver for 3.0 device >>>>> version is doing two things differently: >>>>> 1. Before starting the render process, it invalidates caches (pattern, >>>>> source buffer and mask buffer). Cache control is not present on v4.x >>>>> device. >>>>> 2. Scalling is done through StretchEn command (in BITBLT_COMMAND_REG >>>>> register) instead of SRC_SCALE_CTRL_REG as in v4.x. However the >>>>> exynos_drm_g2d driver does not implement the scalling so this >>>>> difference can be eliminated. >>>> Huh? Where did you get this from? Scaling works with the DRM driver. >>> >>> I was looking for the usage of scaling reg (as there is no scaling >>> command). How the scaling is implemented then? >> Like you said above the drivers work completly different. The DRM one >> receives a command list that is constructed by userspace (libdrm >> mostly), copies it to a contiguous buffer and passes the memory address >> of that buffer to the engine which then works on it. Of course >> everything is slightly more complex. >> >> You don't see any reference to scaling in the driver because the scaling >> regs don't need any kind of specific validation. >> >> If you want to know how the command list is constructed, the best way is >> to look into libdrm. The Exynos specific tests actually cover scaling. > > Thanks for explanations. The patch is insufficient then and it requires > much more effort. Please drop the series as of now. If you intend to add support for v3 hardware we might want to join forces. I have an (ongoing) rewrite of the driver to enable additional functionality and to make it more suitable to provide EXA for a X11 DDX. However this breaks the existing API and rewrites quite a bit of the driver Here's what's there so far. https://github.com/tobiasjakobi/linux-odroid-public/compare/e35ca9aca1214c5e104e6906c1d9affeb80fe5df...3d1ddb86db73b0d664f3e339709e8e8dacdc8e91 And here's the DDX: https://github.com/tobiasjakobi/xf86-video-armsoc/commits/g2d With best wishes, Tobias > > Best regards, > Krzysztof > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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