Re: [PATCH v3 13/14] drm/msm/dp: drop struct msm_dp_panel_in

[Abhinav Kumar <quic_abhinavk@quicinc.com>]

On 12/12/2024 12:53 AM, Dmitry Baryshkov wrote:
> On Thu, 12 Dec 2024 at 05:26, Abhinav Kumar <quic_abhinavk@quicinc.com> wrote:
>>
>>
>>
>> On 12/11/2024 3:41 PM, Dmitry Baryshkov wrote:
>>> All other submodules pass arguments directly. Drop struct
>>> msm_dp_panel_in that is used to wrap dp_panel's submodule args and pass
>>> all data to msm_dp_panel_get() directly.
>>>
>>> Reviewed-by: Stephen Boyd <swboyd@chromium.org>
>>> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>> ---
>>>    drivers/gpu/drm/msm/dp/dp_display.c |  9 +--------
>>>    drivers/gpu/drm/msm/dp/dp_panel.c   | 15 ++++++++-------
>>>    drivers/gpu/drm/msm/dp/dp_panel.h   | 10 ++--------
>>>    3 files changed, 11 insertions(+), 23 deletions(-)
>>>
>>
>> Change not necessarily tied to catalog cleanup, and can be sent
>> independently IMO.
>>
>>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
>>> index cb02d5d5b404925707c737ed75e9e83fbec34f83..a2cdcdac042d63a59ff71aefcecb7f8b22f01167 100644
>>> --- a/drivers/gpu/drm/msm/dp/dp_display.c
>>> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
>>> @@ -722,9 +722,6 @@ static int msm_dp_init_sub_modules(struct msm_dp_display_private *dp)
>>>    {
>>>        int rc = 0;
>>>        struct device *dev = &dp->msm_dp_display.pdev->dev;
>>> -     struct msm_dp_panel_in panel_in = {
>>> -             .dev = dev,
>>> -     };
>>>        struct phy *phy;
>>>
>>>        phy = devm_phy_get(dev, "dp");
>>> @@ -765,11 +762,7 @@ static int msm_dp_init_sub_modules(struct msm_dp_display_private *dp)
>>>                goto error_link;
>>>        }
>>>
>>> -     panel_in.aux = dp->aux;
>>> -     panel_in.catalog = dp->catalog;
>>> -     panel_in.link = dp->link;
>>> -
>>> -     dp->panel = msm_dp_panel_get(&panel_in);
>>> +     dp->panel = msm_dp_panel_get(dev, dp->aux, dp->link, dp->catalog);
>>>        if (IS_ERR(dp->panel)) {
>>>                rc = PTR_ERR(dp->panel);
>>>                DRM_ERROR("failed to initialize panel, rc = %d\n", rc);
>>> diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
>>> index 25869e2ac93aba0bffeddae9f95917d81870d8cb..49bbcde8cf60ac1b297310a50191135d79b092fb 100644
>>> --- a/drivers/gpu/drm/msm/dp/dp_panel.c
>>> +++ b/drivers/gpu/drm/msm/dp/dp_panel.c
>>> @@ -659,25 +659,26 @@ static int msm_dp_panel_parse_dt(struct msm_dp_panel *msm_dp_panel)
>>>        return 0;
>>>    }
>>>
>>> -struct msm_dp_panel *msm_dp_panel_get(struct msm_dp_panel_in *in)
>>> +struct msm_dp_panel *msm_dp_panel_get(struct device *dev, struct drm_dp_aux *aux,
>>> +                           struct msm_dp_link *link, struct msm_dp_catalog *catalog)
>>>    {
>>
>> so this API, takes a filled input panel, makes a msm_dp_panel out of it
>> by filling out more information on top of what was already passed in and
>> returns a msm_dp_panel.
>>
>> So IOW, converts a msm_dp_panel_in to msm_dp_panel.
>>
>> What is the gain by passing individual params rather than passing them
>> as a struct instead? Isnt it better to have it within that struct to
>> show the conversion and moreover we dont have to pass in 4 arguments
>> instead of 1.
> 
> We gain uniformity. All other modules use params. And, as pointed out
> by Maxime during HDMI Codec reviews, it's easier to handle function
> params - it makes it more obvious that one of the params got missing.
> 

Point noted but a very long param list also makes it harder to manage. 
So we should really evaluate on a case-by-case basis and not generalize 
here.

Here its only 4, so i would say its kindof okay. If it goes beyond it, 
then msm_dp_panel_in is probably going to come back.

Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>