On Wed, Nov 13, 2024 at 04:48:31PM +0100, Neil Armstrong wrote:
> The Adreno GMU Management Unit (GMU) can also scale the DDR Bandwidth
> along the Frequency and Power Domain level, until now we left the OPP
> core scale the OPP bandwidth via the interconnect path.
>
> In order to enable bandwidth voting via the GPU Management
> Unit (GMU), when an opp is set by devfreq we also look for
> the corresponding bandwidth index in the previously generated
> bw_table and pass this value along the frequency index to the GMU.
>
> Since we now vote for all resources via the GMU, setting the OPP
> is no more needed, so we can completely skip calling
> dev_pm_opp_set_opp() in this situation.
>
> Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> ---
> drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 17 +++++++++++++++--
> drivers/gpu/drm/msm/adreno/a6xx_gmu.h | 2 +-
> drivers/gpu/drm/msm/adreno/a6xx_hfi.c | 6 +++---
> 3 files changed, 19 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> index 504a7c5d5a9df4c787951f2ae3a69d566d205ad5..1131c3521ebbb0d053aceb162052ed01e197726a 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
> @@ -113,6 +113,7 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp,
> struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
> struct a6xx_gmu *gmu = &a6xx_gpu->gmu;
> u32 perf_index;
> + u32 bw_index = 0;
> unsigned long gpu_freq;
> int ret = 0;
>
> @@ -125,6 +126,16 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp,
> if (gpu_freq == gmu->gpu_freqs[perf_index])
> break;
>
> + /* If enabled, find the corresponding DDR bandwidth index */
> + if ((adreno_gpu->info->quirks & ADRENO_QUIRK_GMU_BW_VOTE) && gmu->nr_gpu_bws) {
> + unsigned int bw = dev_pm_opp_get_bandwidth(opp, true, 0);
> +
> + for (bw_index = 0; bw_index < gmu->nr_gpu_bws - 1; bw_index++) {
> + if (bw == gmu->gpu_bw_table[bw_index])
> + break;
> + }
> + }
> +
> gmu->current_perf_index = perf_index;
> gmu->freq = gmu->gpu_freqs[perf_index];
>
> @@ -140,8 +151,10 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu, struct dev_pm_opp *opp,
> return;
>
> if (!gmu->legacy) {
> - a6xx_hfi_set_freq(gmu, perf_index);
> - dev_pm_opp_set_opp(&gpu->pdev->dev, opp);
> + a6xx_hfi_set_freq(gmu, perf_index, bw_index);
> + /* With Bandwidth voting, we now vote for all resources, so skip OPP set */
> + if (bw_index)
if (!bw_index) ???
Also should there be a 0 vote too in case we are shutting down /
suspending?
> + dev_pm_opp_set_opp(&gpu->pdev->dev, opp);
> return;
> }
>
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
> index 95c632d8987a517f067c48c61c6c06b9a4f61fc0..9b4f2b1a0c48a133cd5c48713bc321c74eaffce9 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.h
> @@ -205,7 +205,7 @@ void a6xx_hfi_init(struct a6xx_gmu *gmu);
> int a6xx_hfi_start(struct a6xx_gmu *gmu, int boot_state);
> void a6xx_hfi_stop(struct a6xx_gmu *gmu);
> int a6xx_hfi_send_prep_slumber(struct a6xx_gmu *gmu);
> -int a6xx_hfi_set_freq(struct a6xx_gmu *gmu, int index);
> +int a6xx_hfi_set_freq(struct a6xx_gmu *gmu, int perf_index, int bw_index);
>
> bool a6xx_gmu_gx_is_on(struct a6xx_gmu *gmu);
> bool a6xx_gmu_sptprac_is_on(struct a6xx_gmu *gmu);
> diff --git a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c b/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
> index 9a89ba95843e7805d78f0e5ddbe328677b6431dd..e2325c15677f1a1194a811e6ecbb5931bdfb1ad9 100644
> --- a/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
> +++ b/drivers/gpu/drm/msm/adreno/a6xx_hfi.c
> @@ -752,13 +752,13 @@ static int a6xx_hfi_send_core_fw_start(struct a6xx_gmu *gmu)
> sizeof(msg), NULL, 0);
> }
>
> -int a6xx_hfi_set_freq(struct a6xx_gmu *gmu, int index)
> +int a6xx_hfi_set_freq(struct a6xx_gmu *gmu, int freq_index, int bw_index)
> {
> struct a6xx_hfi_gx_bw_perf_vote_cmd msg = { 0 };
>
> msg.ack_type = 1; /* blocking */
> - msg.freq = index;
> - msg.bw = 0; /* TODO: bus scaling */
> + msg.freq = freq_index;
> + msg.bw = bw_index;
>
> return a6xx_hfi_send_msg(gmu, HFI_H2F_MSG_GX_BW_PERF_VOTE, &msg,
> sizeof(msg), NULL, 0);
>
> --
> 2.34.1
>
--
With best wishes
Dmitry
