On 1/9/2025 6:02 PM, Dmitry Baryshkov wrote:
On Thu, Jan 09, 2025 at 05:40:23PM -0800, Abhinav Kumar wrote:
On 1/5/2025 7:07 PM, Dmitry Baryshkov wrote:
The fix_core_ab_vote is an average bandwidth value, used for bandwidth
overrides in several cases. However there is an internal inconsistency:
fix_core_ib_vote is defined in KBps, while fix_core_ab_vote is defined
in Bps.
Fix that by changing the type of the variable to u32 and using * 1000ULL
multiplier when setting up the dpu_core_perf_params::bw_ctl value.
Actually after looking at this, I have another question.
How did you conclude that fix_core_ib_vote is in KBps?
min_dram_ib is in KBps in the catalog but how is fix_core_ib_vote?
It depends on the interpretation perhaps. If the debugfs was supposed to
operate under the expectation that the provided value will be pre-multiplied
by 1000 and given then that explains why it was not multiplied again.
And I cross-checked some of the internal usages of the debugfs, the values
provided to it were in Bps and not KBps.
Well... As you wrote min_dram_ib is in KBps. So, by comparing the next
two lines, fix_core_ib_vote should also be in kBps, as there is no
premultiplier:
perf->max_per_pipe_ib = core_perf->fix_core_ib_vote;
[...]
perf->max_per_pipe_ib = perf_cfg->min_dram_ib;
And then, as a proof, perf->max_per_pipe_ib is passed to icc_set_bw()
without any modifications:
icc_set_bw(kms->path[i], avg_bw, perf.max_per_pipe_ib);
Understood max_per_pipe_ib. But then by the same logic, fix_core_ab_vote
is always in Bps and not in KBps because bw_ctl is in Bps.
Is it really a discrepancy that fix_core_ib_vote is defined in KBps,
while fix_core_ab_vote is defined in Bps because they are just following
the units in which bw_ctl and max_per_pipe_ib were defined in resp.
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c | 4 ++--
drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.h | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
index 7263ab63a692554cd51a7fd91bd6250330179240..7cabc8f26908cfd2dbbffebd7c70fc37d9159733 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.c
@@ -125,7 +125,7 @@ static void _dpu_core_perf_calc_crtc(const struct dpu_core_perf *core_perf,
perf->max_per_pipe_ib = 0;
perf->core_clk_rate = 0;
} else if (core_perf->perf_tune.mode == DPU_PERF_MODE_FIXED) {
- perf->bw_ctl = core_perf->fix_core_ab_vote;
+ perf->bw_ctl = core_perf->fix_core_ab_vote * 1000ULL;
perf->max_per_pipe_ib = core_perf->fix_core_ib_vote;
perf->core_clk_rate = core_perf->fix_core_clk_rate;
} else {
@@ -479,7 +479,7 @@ int dpu_core_perf_debugfs_init(struct dpu_kms *dpu_kms, struct dentry *parent)
&perf->fix_core_clk_rate);
debugfs_create_u32("fix_core_ib_vote", 0600, entry,
&perf->fix_core_ib_vote);
- debugfs_create_u64("fix_core_ab_vote", 0600, entry,
+ debugfs_create_u32("fix_core_ab_vote", 0600, entry,
&perf->fix_core_ab_vote);
return 0;
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.h
index ca4595b4ec217697849af02446b23ed0857a0295..5e07119c14c6a9ed3413d0eaddbd93df5cc3f79d 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_core_perf.h
@@ -51,7 +51,7 @@ struct dpu_core_perf {
u32 enable_bw_release;
u64 fix_core_clk_rate;
u32 fix_core_ib_vote;
- u64 fix_core_ab_vote;
+ u32 fix_core_ab_vote;
};
int dpu_core_perf_crtc_check(struct drm_crtc *crtc,
