2021-04-01 18:01:55

by Dmitry Baryshkov

[permalink] [raw]
Subject: Re: [Freedreno] [v1] drm/msm/disp/dpu1: fix warn stack reported during dpu resume

On Thu, 1 Apr 2021 at 16:19, <[email protected]> wrote:
>
> On 2021-04-01 07:37, Dmitry Baryshkov wrote:
> > On 01/04/2021 01:47, Rob Clark wrote:
> >> On Wed, Mar 31, 2021 at 9:03 AM Dmitry Baryshkov
> >> <[email protected]> wrote:
> >>>
> >>> On 31/03/2021 14:27, Kalyan Thota wrote:
> >>>> WARN_ON was introduced by the below commit to catch runtime resumes
> >>>> that are getting triggered before icc path was set.
> >>>>
> >>>> "drm/msm/disp/dpu1: icc path needs to be set before dpu runtime
> >>>> resume"
> >>>>
> >>>> For the targets where the bw scaling is not enabled, this WARN_ON is
> >>>> a false alarm. Fix the WARN condition appropriately.
> >>>
> >>> Should we change all DPU targets to use bw scaling to the mdp from
> >>> the
> >>> mdss nodes? The limitation to sc7180 looks artificial.
> >>
> >> yes, we should, this keeps biting us on 845
> >
> > Done,
> > https://lore.kernel.org/linux-arm-msm/[email protected]/
>
> Hi Dmitry,
>
> https://lore.kernel.org/linux-arm-msm/[email protected]/
>
> you need to add clk_inefficiency_factor, bw_inefficiency_factor in the
> catalogue for the new
> targets where bw scaling is being enabled. please reuse sc7180 values.

Done in patch 1 in that series.

>
> secondly, the AXI clock needs to be moved from mdss to mdp device like
> as in sc7180 dt if its not done already.

Is this enough:
sm8250 has <&gcc GCC_DISP_HF_AXI_CLK> both in mdss and mdp nodes
sdm845 has <&gcc GCC_DISP_AXI_CLK> in mdss node and <&dispcc
DISP_CC_MDSS_AXI_CLK> in the mdp node.


>
> lastly, if you are planning to remove the static votes from dpu_mdss, do
> you also want to move the
> interconnect paths from mdss device to mdp device in the dt ?

I have no strong opinion on this. So far I did not change dt to be
compatible with the current device trees.

>
>
> Thanks,
> Kalyan
>
> >
> >>
> >>>>
> >>>> Reported-by: Steev Klimaszewski <[email protected]>
> >>
> >> Please add Fixes: tag as well
> Adding Fixes tag above my sign-off, should i push another version or can
> it be picked from here ?
>
> Fixes: Id252b9c2887 ("drm/msm/disp/dpu1: icc path needs to be set before
> dpu runtime resume")
> >>
> >>>> Signed-off-by: Kalyan Thota <[email protected]>
> >>>> ---
> >>>> drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 8 +++++---
> >>>> drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h | 9 +++++++++
> >>>> drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c | 11 ++++++-----
> >>>> 3 files changed, 20 insertions(+), 8 deletions(-)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> >>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> >>>> index cab387f..0071a4d 100644
> >>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> >>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> >>>> @@ -294,6 +294,9 @@ static int
> >>>> dpu_kms_parse_data_bus_icc_path(struct dpu_kms *dpu_kms)
> >>>> struct icc_path *path1;
> >>>> struct drm_device *dev = dpu_kms->dev;
> >>>>
> >>>> + if (!dpu_supports_bw_scaling(dev))
> >>>> + return 0;
> >>>> +
> >>>> path0 = of_icc_get(dev->dev, "mdp0-mem");
> >>>> path1 = of_icc_get(dev->dev, "mdp1-mem");
> >>>>
> >>>> @@ -934,8 +937,7 @@ static int dpu_kms_hw_init(struct msm_kms *kms)
> >>>> DPU_DEBUG("REG_DMA is not defined");
> >>>> }
> >>>>
> >>>> - if (of_device_is_compatible(dev->dev->of_node,
> >>>> "qcom,sc7180-mdss"))
> >>>> - dpu_kms_parse_data_bus_icc_path(dpu_kms);
> >>>> + dpu_kms_parse_data_bus_icc_path(dpu_kms);
> >>>>
> >>>> pm_runtime_get_sync(&dpu_kms->pdev->dev);
> >>>>
> >>>> @@ -1198,7 +1200,7 @@ static int __maybe_unused
> >>>> dpu_runtime_resume(struct device *dev)
> >>>>
> >>>> ddev = dpu_kms->dev;
> >>>>
> >>>> - WARN_ON(!(dpu_kms->num_paths));
> >>>> + WARN_ON((dpu_supports_bw_scaling(ddev) &&
> >>>> !dpu_kms->num_paths));
> >>>> /* Min vote of BW is required before turning on AXI clk */
> >>>> for (i = 0; i < dpu_kms->num_paths; i++)
> >>>> icc_set_bw(dpu_kms->path[i], 0,
> >>>> Bps_to_icc(MIN_IB_BW));
> >>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
> >>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
> >>>> index d6717d6..f7bcc0a 100644
> >>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
> >>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
> >>>> @@ -154,6 +154,15 @@ struct vsync_info {
> >>>>
> >>>> #define to_dpu_global_state(x) container_of(x, struct
> >>>> dpu_global_state, base)
> >>>>
> >>>> +/**
> >>>> + * dpu_supports_bw_scaling: returns true for drivers that support
> >>>> bw scaling.
> >>>> + * @dev: Pointer to drm_device structure
> >>>> + */
> >>>> +static inline int dpu_supports_bw_scaling(struct drm_device *dev)
> >>>> +{
> >>>> + return of_device_is_compatible(dev->dev->of_node,
> >>>> "qcom,sc7180-mdss");
> >>>> +}
> >>>> +
> >>>> /* Global private object state for tracking resources that are
> >>>> shared across
> >>>> * multiple kms objects (planes/crtcs/etc).
> >>>> */
> >>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
> >>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
> >>>> index cd40788..8cd712c 100644
> >>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
> >>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
> >>>> @@ -41,6 +41,9 @@ static int dpu_mdss_parse_data_bus_icc_path(struct
> >>>> drm_device *dev,
> >>>> struct icc_path *path0 = of_icc_get(dev->dev, "mdp0-mem");
> >>>> struct icc_path *path1 = of_icc_get(dev->dev, "mdp1-mem");
> >>>>
> >>>> + if (dpu_supports_bw_scaling(dev))
> >>>> + return 0;
> >>>> +
> >>>> if (IS_ERR_OR_NULL(path0))
> >>>> return PTR_ERR_OR_ZERO(path0);
> >>>>
> >>>> @@ -276,11 +279,9 @@ int dpu_mdss_init(struct drm_device *dev)
> >>>>
> >>>> DRM_DEBUG("mapped mdss address space @%pK\n",
> >>>> dpu_mdss->mmio);
> >>>>
> >>>> - if (!of_device_is_compatible(dev->dev->of_node,
> >>>> "qcom,sc7180-mdss")) {
> >>>> - ret = dpu_mdss_parse_data_bus_icc_path(dev, dpu_mdss);
> >>>> - if (ret)
> >>>> - return ret;
> >>>> - }
> >>>> + ret = dpu_mdss_parse_data_bus_icc_path(dev, dpu_mdss);
> >>>> + if (ret)
> >>>> + return ret;
> >>>>
> >>>> mp = &dpu_mdss->mp;
> >>>> ret = msm_dss_parse_clock(pdev, mp);
> >>>>
> >>>
> >>>
> >>> --
> >>> With best wishes
> >>> Dmitry



--
With best wishes
Dmitry


2021-04-02 11:44:51

by Kalyan Thota

[permalink] [raw]
Subject: Re: [Freedreno] [v1] drm/msm/disp/dpu1: fix warn stack reported during dpu resume

On 2021-04-01 19:01, Dmitry Baryshkov wrote:
> On Thu, 1 Apr 2021 at 16:19, <[email protected]> wrote:
>>
>> On 2021-04-01 07:37, Dmitry Baryshkov wrote:
>> > On 01/04/2021 01:47, Rob Clark wrote:
>> >> On Wed, Mar 31, 2021 at 9:03 AM Dmitry Baryshkov
>> >> <[email protected]> wrote:
>> >>>
>> >>> On 31/03/2021 14:27, Kalyan Thota wrote:
>> >>>> WARN_ON was introduced by the below commit to catch runtime resumes
>> >>>> that are getting triggered before icc path was set.
>> >>>>
>> >>>> "drm/msm/disp/dpu1: icc path needs to be set before dpu runtime
>> >>>> resume"
>> >>>>
>> >>>> For the targets where the bw scaling is not enabled, this WARN_ON is
>> >>>> a false alarm. Fix the WARN condition appropriately.
>> >>>
>> >>> Should we change all DPU targets to use bw scaling to the mdp from
>> >>> the
>> >>> mdss nodes? The limitation to sc7180 looks artificial.
>> >>
>> >> yes, we should, this keeps biting us on 845
>> >
>> > Done,
>> > https://lore.kernel.org/linux-arm-msm/[email protected]/
>>
>> Hi Dmitry,
>>
>> https://lore.kernel.org/linux-arm-msm/[email protected]/
>>
>> you need to add clk_inefficiency_factor, bw_inefficiency_factor in the
>> catalogue for the new
>> targets where bw scaling is being enabled. please reuse sc7180 values.
>
> Done in patch 1 in that series.
>
got it.

>>
>> secondly, the AXI clock needs to be moved from mdss to mdp device like
>> as in sc7180 dt if its not done already.
>
> Is this enough:
> sm8250 has <&gcc GCC_DISP_HF_AXI_CLK> both in mdss and mdp nodes
> sdm845 has <&gcc GCC_DISP_AXI_CLK> in mdss node and <&dispcc
> DISP_CC_MDSS_AXI_CLK> in the mdp node.
>
> Since there is no BW vote in mdss, we need to move the AXI clock ON to
> mdp node.

for sm8250
remove GCC_DISP_HF_AXI_CLK from mdss device and add it in mdp device.

for sdm845
remove GCC_DISP_AXI_CLK from mdss device and add it in mdp device before
we turn on DISP_CC_MDSS_AXI_CLK, i.e as first item.

>>
>> lastly, if you are planning to remove the static votes from dpu_mdss,
>> do
>> you also want to move the
>> interconnect paths from mdss device to mdp device in the dt ?
>
> I have no strong opinion on this. So far I did not change dt to be
> compatible with the current device trees.
>
>>
>>
>> Thanks,
>> Kalyan
>>
>> >
>> >>
>> >>>>
>> >>>> Reported-by: Steev Klimaszewski <[email protected]>
>> >>
>> >> Please add Fixes: tag as well
>> Adding Fixes tag above my sign-off, should i push another version or
>> can
>> it be picked from here ?
>>
>> Fixes: 627dc55c273d ("drm/msm/disp/dpu1: icc path needs to be set
>> before
>> dpu runtime resume")
>> >>
>> >>>> Signed-off-by: Kalyan Thota <[email protected]>
>> >>>> ---
>> >>>> drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c | 8 +++++---
>> >>>> drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h | 9 +++++++++
>> >>>> drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c | 11 ++++++-----
>> >>>> 3 files changed, 20 insertions(+), 8 deletions(-)
>> >>>>
>> >>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>> >>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>> >>>> index cab387f..0071a4d 100644
>> >>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>> >>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>> >>>> @@ -294,6 +294,9 @@ static int
>> >>>> dpu_kms_parse_data_bus_icc_path(struct dpu_kms *dpu_kms)
>> >>>> struct icc_path *path1;
>> >>>> struct drm_device *dev = dpu_kms->dev;
>> >>>>
>> >>>> + if (!dpu_supports_bw_scaling(dev))
>> >>>> + return 0;
>> >>>> +
>> >>>> path0 = of_icc_get(dev->dev, "mdp0-mem");
>> >>>> path1 = of_icc_get(dev->dev, "mdp1-mem");
>> >>>>
>> >>>> @@ -934,8 +937,7 @@ static int dpu_kms_hw_init(struct msm_kms *kms)
>> >>>> DPU_DEBUG("REG_DMA is not defined");
>> >>>> }
>> >>>>
>> >>>> - if (of_device_is_compatible(dev->dev->of_node,
>> >>>> "qcom,sc7180-mdss"))
>> >>>> - dpu_kms_parse_data_bus_icc_path(dpu_kms);
>> >>>> + dpu_kms_parse_data_bus_icc_path(dpu_kms);
>> >>>>
>> >>>> pm_runtime_get_sync(&dpu_kms->pdev->dev);
>> >>>>
>> >>>> @@ -1198,7 +1200,7 @@ static int __maybe_unused
>> >>>> dpu_runtime_resume(struct device *dev)
>> >>>>
>> >>>> ddev = dpu_kms->dev;
>> >>>>
>> >>>> - WARN_ON(!(dpu_kms->num_paths));
>> >>>> + WARN_ON((dpu_supports_bw_scaling(ddev) &&
>> >>>> !dpu_kms->num_paths));
>> >>>> /* Min vote of BW is required before turning on AXI clk */
>> >>>> for (i = 0; i < dpu_kms->num_paths; i++)
>> >>>> icc_set_bw(dpu_kms->path[i], 0,
>> >>>> Bps_to_icc(MIN_IB_BW));
>> >>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
>> >>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
>> >>>> index d6717d6..f7bcc0a 100644
>> >>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
>> >>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
>> >>>> @@ -154,6 +154,15 @@ struct vsync_info {
>> >>>>
>> >>>> #define to_dpu_global_state(x) container_of(x, struct
>> >>>> dpu_global_state, base)
>> >>>>
>> >>>> +/**
>> >>>> + * dpu_supports_bw_scaling: returns true for drivers that support
>> >>>> bw scaling.
>> >>>> + * @dev: Pointer to drm_device structure
>> >>>> + */
>> >>>> +static inline int dpu_supports_bw_scaling(struct drm_device *dev)
>> >>>> +{
>> >>>> + return of_device_is_compatible(dev->dev->of_node,
>> >>>> "qcom,sc7180-mdss");
>> >>>> +}
>> >>>> +
>> >>>> /* Global private object state for tracking resources that are
>> >>>> shared across
>> >>>> * multiple kms objects (planes/crtcs/etc).
>> >>>> */
>> >>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
>> >>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
>> >>>> index cd40788..8cd712c 100644
>> >>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
>> >>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_mdss.c
>> >>>> @@ -41,6 +41,9 @@ static int dpu_mdss_parse_data_bus_icc_path(struct
>> >>>> drm_device *dev,
>> >>>> struct icc_path *path0 = of_icc_get(dev->dev, "mdp0-mem");
>> >>>> struct icc_path *path1 = of_icc_get(dev->dev, "mdp1-mem");
>> >>>>
>> >>>> + if (dpu_supports_bw_scaling(dev))
>> >>>> + return 0;
>> >>>> +
>> >>>> if (IS_ERR_OR_NULL(path0))
>> >>>> return PTR_ERR_OR_ZERO(path0);
>> >>>>
>> >>>> @@ -276,11 +279,9 @@ int dpu_mdss_init(struct drm_device *dev)
>> >>>>
>> >>>> DRM_DEBUG("mapped mdss address space @%pK\n",
>> >>>> dpu_mdss->mmio);
>> >>>>
>> >>>> - if (!of_device_is_compatible(dev->dev->of_node,
>> >>>> "qcom,sc7180-mdss")) {
>> >>>> - ret = dpu_mdss_parse_data_bus_icc_path(dev, dpu_mdss);
>> >>>> - if (ret)
>> >>>> - return ret;
>> >>>> - }
>> >>>> + ret = dpu_mdss_parse_data_bus_icc_path(dev, dpu_mdss);
>> >>>> + if (ret)
>> >>>> + return ret;
>> >>>>
>> >>>> mp = &dpu_mdss->mp;
>> >>>> ret = msm_dss_parse_clock(pdev, mp);
>> >>>>
>> >>>
>> >>>
>> >>> --
>> >>> With best wishes
>> >>> Dmitry