Re: [Intel-gfx] [PATCH 2/6] drm/i915/display: add cdclk action struct to cdclk_config

[Jani Nikula <jani.nikula@linux.intel.com>]

On Mon, 19 Sep 2022, "Srivatsa, Anusha" <anusha.srivatsa@intel.com> wrote:
>> -----Original Message-----
>> From: Navare, Manasi D <manasi.d.navare@intel.com>
>> Sent: Monday, September 19, 2022 12:33 PM
>> To: Jani Nikula <jani.nikula@linux.intel.com>
>> Cc: Srivatsa, Anusha <anusha.srivatsa@intel.com>; intel-
>> gfx@lists.freedesktop.org
>> Subject: Re: [Intel-gfx] [PATCH 2/6] drm/i915/display: add cdclk action struct
>> to cdclk_config
>> 
>> On Mon, Sep 19, 2022 at 12:26:19PM +0300, Jani Nikula wrote:
>> > On Fri, 16 Sep 2022, Anusha Srivatsa <anusha.srivatsa@intel.com> wrote:
>> > > The struct has the action to be performed - squash, crawl or modeset
>> > > and the corresponding cdclk which is the desired cdclk. This is the
>> > > structure that gets populated during atomic check once it is
>> > > determined what the cdclk change looks like
>> > >
>> > > Signed-off-by: Anusha Srivatsa <anusha.srivatsa@intel.com>
>> > > ---
>> > >  drivers/gpu/drm/i915/display/intel_cdclk.h | 14 ++++++++++++++
>> > >  1 file changed, 14 insertions(+)
>> > >
>> > > diff --git a/drivers/gpu/drm/i915/display/intel_cdclk.h
>> > > b/drivers/gpu/drm/i915/display/intel_cdclk.h
>> > > index c674879a84a5..3869f93e8ad2 100644
>> > > --- a/drivers/gpu/drm/i915/display/intel_cdclk.h
>> > > +++ b/drivers/gpu/drm/i915/display/intel_cdclk.h
>> > > @@ -11,13 +11,27 @@
>> > >  #include "intel_display.h"
>> > >  #include "intel_global_state.h"
>> > >
>> > > +#define	MAX_CDCLK_ACTIONS	1
>> >
>> > Okay, this review is just nitpicks, but they'll need to get fixed
>> > eventually so here goes.
>> >
>> > No tab after #define.
>> >
>> > > +
>> > >  struct drm_i915_private;
>> > >  struct intel_atomic_state;
>> > >  struct intel_crtc_state;
>> > >
>> > > +enum cdclk_sequence {
>> >
>> > Needs to be named intel_ something.
>> 
>> Agree here
>
> Agree with all the above. Will make the suitable changes.
>
>> >
>> > > +	CDCLK_INVALID_ACTION = -1,
>> > > +
>> > > +	CDCLK_SQUASH_ONLY = 0,
>> > > +	CDCLK_CRAWL_ONLY,
>> > > +	CDCLK_LEGACY,
>> > > +};
>> > > +
>> > >  struct intel_cdclk_config {
>> > >  	unsigned int cdclk, vco, ref, bypass;
>> > >  	u8 voltage_level;
>> > > +	struct cdclk_step {
>> >
>> > Needs to be named intel_ something.
>> >
>> > Since this is used independently, I'd prefer it to be defined outside
>> > of struct intel_cdclk_config.
>> 
>> I think the point of having it as part of intel_cdclk_config is that because we
>> already pass cdclk_config to set_cdclk where these actions are going to get
>> used.
>
> Yes. That is correct. This eventually gets used in bxt_set_cdclk() and
> we are already passing cdclk_config there. Having this new struct
> embedded in cdclk_config makes the fields - action and cdclk to be
> accessible without having to change the function signature of
> set_cdclk()

I referred to defining the *type* outside of struct intel_cdclk_config.

Contrast

	struct foo {
		struct bar {
			...
		} baz;
	};

with

	struct bar {
		...
	};

	struct foo {
		struct bar baz;
	};

when you actually use struct bar for parameters and local variables.

BR,
Jani.


>
> Anusha
>> Manasi
>> 
>> >
>> > > +		enum cdclk_sequence action;
>> > > +		u32 cdclk;
>> > > +	} steps[MAX_CDCLK_ACTIONS];
>> > >  };
>> > >
>> > >  struct intel_cdclk_state {
>> >
>> > --
>> > Jani Nikula, Intel Open Source Graphics Center

-- 
Jani Nikula, Intel Open Source Graphics Center