On 14/12/2024 00:46, Konrad Dybcio wrote:
On 13.12.2024 5:55 PM, Akhil P Oommen wrote:
On 12/13/2024 10:10 PM, neil.armstrong@xxxxxxxxxx wrote:
On 13/12/2024 17:31, Konrad Dybcio wrote:
On 13.12.2024 5:28 PM, neil.armstrong@xxxxxxxxxx wrote:
On 13/12/2024 16:37, Konrad Dybcio wrote:
On 13.12.2024 2:12 PM, Akhil P Oommen wrote:
On 12/13/2024 3:07 AM, Neil Armstrong wrote:
On 12/12/2024 21:21, Konrad Dybcio wrote:
On 11.12.2024 9:29 AM, Neil Armstrong wrote:
The Adreno GPU 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.
The GMU also takes another vote called AB which is a 16bit
quantized
value of the floor bandwidth against the maximum supported
bandwidth.
The AB is calculated with a default 25% of the bandwidth like the
downstream implementation too inform the GMU firmware the minimal
quantity of bandwidth we require for this OPP.
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.
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Reviewed-by: Akhil P Oommen <quic_akhilpo@xxxxxxxxxxx>
Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
---
drivers/gpu/drm/msm/adreno/a6xx_gmu.c | 39 +++++++++++++++++
+++++++
+++++++++--
drivers/gpu/drm/msm/adreno/a6xx_gmu.h | 2 +-
drivers/gpu/drm/msm/adreno/a6xx_hfi.c | 6 +++---
drivers/gpu/drm/msm/adreno/a6xx_hfi.h | 5 +++++
4 files changed, 46 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c b/drivers/
gpu/drm/
msm/adreno/a6xx_gmu.c
index
36696d372a42a27b26a018b19e73bc6d8a4a5235..46ae0ec7a16a41d55755ce04fb32404cdba087be 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gmu.c
@@ -110,9 +110,11 @@ void a6xx_gmu_set_freq(struct msm_gpu *gpu,
struct dev_pm_opp *opp,
bool suspended)
{
struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
+ const struct a6xx_info *info = adreno_gpu->info->a6xx;
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 +127,37 @@ 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 (info->bcms && gmu->nr_gpu_bws > 1) {
if (gmu->nr_gpu_bws)
gmu->nr_gpu_bws == 1 means there's not BW in the OPPs (index 0 is the
"off" state)
+ unsigned int bw = dev_pm_opp_get_bw(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;
+ }
+
+ /* Vote AB as a fraction of the max bandwidth */
+ if (bw) {
This seems to only be introduced with certain a7xx too.. you should
ping the GMU with HFI_VALUE_GMU_AB_VOTE to check if it's supported
Good point
No no. Doing this will trigger some assert in pre-A750 gmu
firmwares. We
learned it the hard way. No improvisation please. :)
We shouldn't be sending that AB data to firmware that doesn't expect
it either too, though..
Well we don't !
The code in the scope that I quoted above does that
No it doesn't, if the proper bcms are not declared in the gpu_info, it
won't
I think what Konrad meant was that IB voting is supported from a650+,
but AB voting is support only from a750+. So we can add bcm nodes to
enable IB voting, but how do we ensure AB voting via GMU is done only on
a750+.
Yep, relying on incomplete data in the catalog is not a great way
to ensure that
I understood correctly, so I'll add a bool to enable AB voting, but please
don't ask me to remove it because it's dead code and useless if only
enabled on a750+...
Neil
Konrad
