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Message-ID: <188e0168-a45b-6e38-ac49-8b0fd41e9110@quicinc.com>
Date:   Fri, 8 Dec 2023 08:33:48 -0800
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Subject: Re: [PATCH v2 14/16] drm/msm/dpu: reserve cdm blocks for writeback in
 case of YUV output
Content-Language: en-US
To:     Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
CC:     <freedreno@lists.freedesktop.org>, Rob Clark <robdclark@gmail.com>,
        "Sean Paul" <sean@poorly.run>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        "David Airlie" <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        <dri-devel@lists.freedesktop.org>, <quic_jesszhan@quicinc.com>,
        <quic_parellan@quicinc.com>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <20231208050641.32582-1-quic_abhinavk@quicinc.com>
 <20231208050641.32582-15-quic_abhinavk@quicinc.com>
 <CAA8EJpo4XVMJ7RqsZZ6Eh_PjoPeWiMmAW3P1a4dkZ_EHqz7GkQ@mail.gmail.com>
From:   Abhinav Kumar <quic_abhinavk@quicinc.com>
In-Reply-To: <CAA8EJpo4XVMJ7RqsZZ6Eh_PjoPeWiMmAW3P1a4dkZ_EHqz7GkQ@mail.gmail.com>
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On 12/8/2023 3:54 AM, Dmitry Baryshkov wrote:
> On Fri, 8 Dec 2023 at 07:07, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote:
>>
>> Reserve CDM blocks for writeback if the format of the output fb
>> is YUV. At the moment, the reservation is done only for writeback
>> but can easily be extended by relaxing the checks once other
>> interfaces are ready to output YUV.
>>
>> changes in v2:
>>          - use needs_cdm from topology struct
>>          - drop fb related checks from atomic_mode_set()
> 
> It looks like this should be squashed with the patch 11. The 'unbind
> CDM' doesn't really make sense without this patch. We need to allocate
> it first,  before touching it.
> 

The way I was thinking was that patch just completes the 
dpu_encoder_phys_cleanup() and yes it was intentionally kept ahead 
because that will not kick in till hw_cdm is assigned.

Then, this patch only handles reserving/assignment of hw_cdm when needed.

That was the motivation behind this split.

>>
>> Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
>> ---
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 27 +++++++++++++++++++++
>>   1 file changed, 27 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> index 862912727925..a576e3e62429 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> @@ -16,6 +16,7 @@
>>   #include <drm/drm_crtc.h>
>>   #include <drm/drm_file.h>
>>   #include <drm/drm_probe_helper.h>
>> +#include <drm/drm_framebuffer.h>
>>
>>   #include "msm_drv.h"
>>   #include "dpu_kms.h"
>> @@ -583,6 +584,7 @@ static int dpu_encoder_virt_atomic_check(
>>          struct drm_display_mode *adj_mode;
>>          struct msm_display_topology topology;
>>          struct dpu_global_state *global_state;
>> +       struct drm_framebuffer *fb;
>>          struct drm_dsc_config *dsc;
>>          int i = 0;
>>          int ret = 0;
>> @@ -623,6 +625,22 @@ static int dpu_encoder_virt_atomic_check(
>>
>>          topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, adj_mode, crtc_state, dsc);
>>
>> +       /*
>> +        * Use CDM only for writeback at the moment as other interfaces cannot handle it.
>> +        * if writeback itself cannot handle cdm for some reason it will fail in its atomic_check()
>> +        * earlier.
>> +        */
>> +       if (dpu_enc->disp_info.intf_type == INTF_WB && conn_state->writeback_job) {
>> +               fb = conn_state->writeback_job->fb;
>> +
>> +               if (fb && DPU_FORMAT_IS_YUV(to_dpu_format(msm_framebuffer_format(fb))))
>> +                       topology.needs_cdm = true;
>> +               if (topology.needs_cdm && !dpu_enc->cur_master->hw_cdm)
>> +                       crtc_state->mode_changed = true;
>> +               else if (!topology.needs_cdm && dpu_enc->cur_master->hw_cdm)
>> +                       crtc_state->mode_changed = true;
>> +       }
>> +
>>          /*
>>           * Release and Allocate resources on every modeset
>>           * Dont allocate when active is false.
>> @@ -1063,6 +1081,15 @@ static void dpu_encoder_virt_atomic_mode_set(struct drm_encoder *drm_enc,
>>
>>          dpu_enc->dsc_mask = dsc_mask;
>>
>> +       if (dpu_enc->disp_info.intf_type == INTF_WB && conn_state->writeback_job) {
>> +               struct dpu_hw_blk *hw_cdm = NULL;
>> +
>> +               dpu_rm_get_assigned_resources(&dpu_kms->rm, global_state,
>> +                                             drm_enc->base.id, DPU_HW_BLK_CDM,
>> +                                             &hw_cdm, 1);
>> +               dpu_enc->cur_master->hw_cdm = hw_cdm ? to_dpu_hw_cdm(hw_cdm) : NULL;
>> +       }
>> +
>>          cstate = to_dpu_crtc_state(crtc_state);
>>
>>          for (i = 0; i < num_lm; i++) {
>> --
>> 2.40.1
>>
> 
> 
> --
> With best wishes
> 
> Dmitry