On 23.10.19 г. 15:47 ч., Brian Masney wrote: > On Wed, Oct 23, 2019 at 02:50:19PM +0300, Georgi Djakov wrote: >> On 13.10.19 г. 11:08 ч., Brian Masney wrote: >>> Add interconnect nodes that's needed to support bus scaling. >>> >>> Signed-off-by: Brian Masney <[email protected]> >>> --- >>> arch/arm/boot/dts/qcom-msm8974.dtsi | 60 +++++++++++++++++++++++++++++ >>> 1 file changed, 60 insertions(+) >>> >>> diff --git a/arch/arm/boot/dts/qcom-msm8974.dtsi >>> b/arch/arm/boot/dts/qcom-msm8974.dtsi >>> @@ -1152,6 +1207,11 @@ >>> "core", >>> "vsync"; >>> >>> + interconnects = <&mmssnoc MNOC_MAS_GRAPHICS_3D >>> &bimc BIMC_SLV_EBI_CH0>, >>> + <&ocmemnoc OCMEM_VNOC_MAS_GFX3D >>> &ocmemnoc OCMEM_SLV_OCMEM>; >> >> Who will be the requesting bandwidth to DDR and ocmem? Is it the display or >> GPU >> or both? The above seem like GPU-related interconnects, so maybe these >> properties should be in the GPU DT node. > > The display is what currently requests the interconnect path, > specifically mdp5_setup_interconnect() in > drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c. The Freedreno GPU bindings > currently don't have interconnect support. Maybe this is something that > I should add to that driver as well?
The "mdp0-mem" and "mdp1-mem" paths mentioned in the mdp5_kms.c are the two interconnects between the display and DDR memory. There is actually a patch [1] to add to GPU bindings, but it seems that we missed to pick it up. > >>> + interconnect-names = "mdp0-mem", >>> + "mdp1-mem"; >> >> As the second path is not to DDR, but to ocmem, it might be better to call it >> something like "gpu-ocmem". > > I used what mdp5_kms.c expected. This is for the display and here [2] are some patches for the GPU. Not sure how the NoCs are configured on 8974 by default, but if you notice any blue/black screens, you may need to request bandwidth for display too. Thanks, Georgi [1] https://lore.kernel.org/r/[email protected] [2] https://lore.kernel.org/r/[email protected]
