linux-kernel - Re: [PATCH v1 2/3] drm/msm/dp: decoupling dp->id out of dp controller_id at scxxxx_dp

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Message-ID: <66ff4642-f268-f5b0-7e28-b196368c508a@quicinc.com>
Date:   Fri, 24 Jun 2022 16:56:34 -0700
From:   Kuogee Hsieh <quic_khsieh@...cinc.com>
To:     Stephen Boyd <swboyd@...omium.org>, <agross@...nel.org>,
        <airlied@...ux.ie>, <bjorn.andersson@...aro.org>,
        <daniel@...ll.ch>, <dianders@...omium.org>,
        <dmitry.baryshkov@...aro.org>, <dri-devel@...ts.freedesktop.org>,
        <robdclark@...il.com>, <sean@...rly.run>, <vkoul@...nel.org>
CC:     <quic_abhinavk@...cinc.com>, <quic_aravindh@...cinc.com>,
        <quic_sbillaka@...cinc.com>, <freedreno@...ts.freedesktop.org>,
        <linux-arm-msm@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v1 2/3] drm/msm/dp: decoupling dp->id out of dp
 controller_id at scxxxx_dp_cfg table


On 6/24/2022 4:45 PM, Stephen Boyd wrote:
> Quoting Kuogee Hsieh (2022-06-24 16:30:59)
>> On 6/24/2022 4:12 PM, Stephen Boyd wrote:
>>> Quoting Kuogee Hsieh (2022-06-24 15:53:45)
>>>> MSM_DP_CONTROLLER_1 need to match to the index = 1 of sc7280_dp_cfg[] <== This is correct
>>>>
>>>> The problem is sc7280_dp_cfg[] have two entries since eDP place at index
>>>> of MSM_DP_CONTROLLER_1.
>>>>
>>>> but .num_desc = 1  <== this said only have one entry at sc7280_dp_cfg[]
>>>> table. Therefore eDP will never be found at for loop  at
>>>> _dpu_kms_initialize_displayport().
>>>>
>>> Yes, but what else does the MSM_DP_CONTROLLER_1 need to match? Because
>>> the intention of the previous commit was to make it so the order of
>>> sc7280_dp_cfg couldn't be messed up and not match the
>>> MSM_DP_CONTROLLER_1 value that lives in sc7280_intf[].
>>
>> at  _dpu_kms_initialize_displayport()
>>
>>> -             info.h_tile_instance[0] = i; <== assign i to become dp controller id, "i" is index of scxxxx_dp_cfg[]
>> This what I mean MSM_DP_CONTROLLER_1 need to match to index = 1 of
>> scxxxx_dp_cfg[].
>>
>> it it is not match, then MSM_DP_CONTROLLER_1 with match to different INTF.
> I thought we matched the INTF instance by searching through
> sc7280_intf[] for a matching MSM_DP_CONTROLLER_1 and then returning that
> INTF number. See dpu_encoder_get_intf() and the caller.

yes, but the controller_id had been over written by dp->id.

u32 controller_id = disp_info->h_tile_instance[i];


See below code.


>          for (i = 0; i < disp_info->num_of_h_tiles && !ret; i++) {
>                  /*
>                   * Left-most tile is at index 0, content is controller id
>                   * h_tile_instance_ids[2] = {0, 1}; DSI0 = left, DSI1 = right
>                   * h_tile_instance_ids[2] = {1, 0}; DSI1 = left, DSI0 = right
>                   */
>                  u32 controller_id = disp_info->h_tile_instance[i];   <== kuogee assign dp->id to controller_id
>
>                  if (disp_info->num_of_h_tiles > 1) {
>                          if (i == 0)
>                                  phys_params.split_role = ENC_ROLE_MASTER;
>                          else
>                                  phys_params.split_role = ENC_ROLE_SLAVE;
>                  } else {
>                          phys_params.split_role = ENC_ROLE_SOLO;
>                  }
>
>                  DPU_DEBUG("h_tile_instance %d = %d, split_role %d\n",
>                                  i, controller_id, phys_params.split_role);
>
>                  phys_params.intf_idx = dpu_encoder_get_intf(dpu_kms->catalog,
>
>                intf_type,
>
>                controller_id);