Am Mittwoch, den 14.12.2016, 09:39 +0100 schrieb Wladimir J. van der
Laan:
> Set up the PULSE_EATER register (0x0010C) in etnaviv_gpu_hw_init. This
> ports three mostly undocumented model/revision-specific register
> overrides from the Vivante kernel driver.
>
> This is relevant as at least the "disable internal DFS" for revisions >
> 0x5420 has shown to have a huge impact on shader performance (sped up
> memory read performance by 7.5x and write performance by 1.5x) on an
> affected GPU.
Missing Singed-off-by
> ---
> drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 30 ++++++++++++++++++++++++++++++
> 1 file changed, 30 insertions(+)
>
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> index 1e0ec81..e1a9d64 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
> @@ -548,6 +548,9 @@ void etnaviv_gpu_start_fe(struct etnaviv_gpu *gpu, u32 address, u16 prefetch)
> VIVS_FE_COMMAND_CONTROL_PREFETCH(prefetch));
> }
>
> +/* base value for VIVS_PM_PULSE_EATER register on models where it cannot be read */
> +#define PULSE_EATER_BASE_VALUE (0x01590880)
> +
Please don't introduce freestanding defines.
> static void etnaviv_gpu_hw_init(struct etnaviv_gpu *gpu)
> {
> u16 prefetch;
> @@ -588,6 +591,33 @@ static void etnaviv_gpu_hw_init(struct etnaviv_gpu *gpu)
> gpu_write(gpu, VIVS_MC_BUS_CONFIG, bus_config);
> }
Please split this out into a separate function like the mlgc setup.
>
> + /* set up the pulse eater */
> + if (etnaviv_is_model_rev(gpu, GC4000, 0x5208) ||
> + etnaviv_is_model_rev(gpu, GC4000, 0x5222)) {
> + /* undocumented workaround from vivante kernel driver */
> + u32 pulse_eater = PULSE_EATER_BASE_VALUE;
If this is in a separate function, the definition of this variable can
move out of the individual blocks. Just have a single
u32 pulse_eater = 0x01590880;
at the top of the function with a comment where this value comes from.
> + pulse_eater |= BIT(23);
> + gpu_write(gpu, VIVS_PM_PULSE_EATER, pulse_eater);
> + }
> +
> + if (etnaviv_is_model_rev(gpu, GC1000, 0x5039) ||
> + etnaviv_is_model_rev(gpu, GC1000, 0x5040)) {
> + /* undocumented workaround from vivante kernel driver */
I'm not sure how much value this comment holds. Most of the PM register
setup consists of undocumented workarounds extracted from the Vivante
driver. But that's a matter of taste, so feel free to remove or keep it.
> + u32 pulse_eater = PULSE_EATER_BASE_VALUE;
> + pulse_eater &= ~BIT(16);
> + pulse_eater |= BIT(17);
> + gpu_write(gpu, VIVS_PM_PULSE_EATER, pulse_eater);
> + }
> +
> + if ((gpu->identity.revision > 0x5420) &&
> + (gpu->identity.features & chipFeatures_PIPE_3D))
> + {
> + /* disable internal DFS: this is extremely important to performance */
> + u32 pulse_eater = gpu_read(gpu, VIVS_PM_PULSE_EATER);
> + pulse_eater |= BIT(18);
> + gpu_write(gpu, VIVS_PM_PULSE_EATER, pulse_eater);
> + }
> +
> /* setup the MMU */
> etnaviv_iommu_restore(gpu);
>
Regards,
Lucas
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