Re: [PATCH 01/10] drm/i915/display: Add helper to compute link M/N ratio for reuse

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

On Fri, 11 Sep 2026, Suraj Kandpal <suraj.kandpal@intel.com> wrote:
> From: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
>
> Introduce `intel_display_get_link_m_n()` to compute the link M/N ratio

Please drop the backticks. IMO it's just ugly fluff in commit messages.

> based on pixel clock and link clock. This logic was previously embedded
> within `intel_link_compute_m_n()`.
>
> The new helper allows reuse of link M/N computation in other contexts
> without requiring the full data M/N calculation.
>
> No functional changes intended.
>
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 18 ++++++++++++++----
>  1 file changed, 14 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index fc30a455bed3..b5682c196646 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -2633,13 +2633,24 @@ static void compute_m_n(u32 *ret_m, u32 *ret_n,
>  	intel_reduce_m_n_ratio(ret_m, ret_n);
>  }
>  
> +static
> +void intel_display_get_link_m_n(u32 *link_m, u32 *link_n,
> +				u32 pixel_clock,
> +				u32 link_clock)

Now we have two functions:

- intel_display_get_link_m_n()
- intel_link_compute_m_n()

in which one is a part of the other, but the names are quite different.

Why? Shouldn't the names be somewhat similar?

BR,
Jani.


> +{
> +	u32 link_symbol_clock = intel_dp_link_symbol_clock(link_clock);
> +
> +	compute_m_n(link_m, link_n,
> +		    pixel_clock, link_symbol_clock,
> +		    0x80000);
> +}
> +
>  void
>  intel_link_compute_m_n(u16 bits_per_pixel_x16, int nlanes,
>  		       int pixel_clock, int link_clock,
>  		       int bw_overhead,
>  		       struct intel_link_m_n *m_n)
>  {
> -	u32 link_symbol_clock = intel_dp_link_symbol_clock(link_clock);
>  	u32 data_m = intel_dp_effective_data_rate(pixel_clock, bits_per_pixel_x16,
>  						  bw_overhead);
>  	u32 data_n = drm_dp_max_dprx_data_rate(link_clock, nlanes);
> @@ -2656,9 +2667,8 @@ intel_link_compute_m_n(u16 bits_per_pixel_x16, int nlanes,
>  		    data_m, data_n,
>  		    0x8000000);
>  
> -	compute_m_n(&m_n->link_m, &m_n->link_n,
> -		    pixel_clock, link_symbol_clock,
> -		    0x80000);
> +	intel_display_get_link_m_n(&m_n->link_m, &m_n->link_n,
> +				   pixel_clock, link_clock);
>  }
>  
>  void intel_panel_sanitize_ssc(struct intel_display *display)

-- 
Jani Nikula, Intel