On Thu, Jun 27, 2024 at 03:22:18AM GMT, Akhil P Oommen wrote: > << snip >> > > > > > > > > @@ -1503,7 +1497,7 @@ static void __iomem *a6xx_gmu_get_mmio(struct platform_device *pdev, > > > > > > > return ERR_PTR(-EINVAL); > > > > > > > } > > > > > > > > > > > > > > - ret = ioremap(res->start, resource_size(res)); > > > > > > > + ret = devm_ioremap_resource(&pdev->dev, res); > > > > > > > > > > > > So, this doesn't actually work, failing in __request_region_locked(), > > > > > > because the gmu region partially overlaps with the gpucc region (which > > > > > > is busy). I think this is intentional, since gmu is controlling the > > > > > > gpu clocks, etc. In particular REG_A6XX_GPU_CC_GX_GDSCR is in this > > > > > > overlapping region. Maybe Akhil knows more about GMU. > > > > > > > > > > We don't really need to map gpucc region from driver on behalf of gmu. > > > > > Since we don't access any gpucc register from drm-msm driver, we can > > > > > update the range size to correct this. But due to backward compatibility > > > > > requirement with older dt, can we still enable region locking? I prefer > > > > > it if that is possible. > > > > > > > > Actually, when I reduced the region size to not overlap with gpucc, > > > > the region is smaller than REG_A6XX_GPU_CC_GX_GDSCR * 4. > > > > > > > > So I guess that register is actually part of gpucc? > > > > > > Yes. It has *GPU_CC* in its name. :P > > > > > > I just saw that we program this register on legacy a6xx targets to > > > ensure retention is really ON before collapsing gdsc. So we can't > > > avoid mapping gpucc region in legacy a6xx GPUs. That is unfortunate! > > > > I guess we could still use devm_ioremap().. idk if there is a better > > way to solve this > > Can we do it without breaking backward compatibility with dt? I think a proper way would be to use devm_ioremap in the gpucc driver, then the GPU driver can use devm_platform_ioremap_resource(). I'll take a look at sketching the gpucc patches in one of the next few days. > > -Akhil > > > > > BR, > > -R > > > > > -Akhil. > > > > > > > > > > > BR, > > > > -R -- With best wishes Dmitry
