[Intel-gfx] [PATCH v1½ 12/13] drm/i915/dp: localize link rate index variable more

[Manasi Navare]

On Thu, Feb 02, 2017 at 10:42:48AM +0200, Jani Nikula wrote:
> On Thu, 02 Feb 2017, Manasi Navare <manasi.d.navare at intel.com> wrote:
> > On Thu, Jan 26, 2017 at 09:44:26PM +0200, Jani Nikula wrote:
> >> Localize link_rate_index to the if block, and rename to just index to
> >> reduce indent.
> >> 
> >> Cc: Manasi Navare <manasi.d.navare at intel.com>
> >> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> >> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> >> ---
> >>  drivers/gpu/drm/i915/intel_dp.c | 13 +++++++------
> >>  1 file changed, 7 insertions(+), 6 deletions(-)
> >> 
> >> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> >> index 7704d32286a3..429dc70c251a 100644
> >> --- a/drivers/gpu/drm/i915/intel_dp.c
> >> +++ b/drivers/gpu/drm/i915/intel_dp.c
> >> @@ -1639,7 +1639,6 @@ intel_dp_compute_config(struct intel_encoder *encoder,
> >>  	/* Conveniently, the link BW constants become indices with a shift...*/
> >>  	int min_clock = 0;
> >>  	int max_clock;
> >> -	int link_rate_index;
> >>  	int bpp, mode_rate;
> >>  	int link_avail, link_clock;
> >>  	const int *common_rates = intel_dp->common_rates;
> >> @@ -1684,11 +1683,13 @@ intel_dp_compute_config(struct intel_encoder *encoder,
> >>  
> >>  	/* Use values requested by Compliance Test Request */
> >>  	if (intel_dp->compliance.test_type == DP_TEST_LINK_TRAINING) {
> >> -		link_rate_index = intel_dp_find_rate(intel_dp->common_rates,
> >> -						     intel_dp->num_common_rates,
> >> -						     intel_dp->compliance.test_link_rate);
> >
> > Can we not pass just the common_rates as an argument to this function
> > since common_rates is already assigned intel_dp->common_rates.
> 
> Do you mean just pass intel_dp to intel_dp_find_rate? If yes, I think
> this keeps intel_dp_find_rate generic, independent of intel_dp or
> anything else, and you can be sure it's stateless (same as
> intersect_rates).
> 
> If you don't mean that, I don't know what you mean... please explain.
> 
> BR,
> Jani.
> 
>

I agree that it needs to be stateless and hence we dont pass intel_dp directly.
What I was saying was that at the beginning of the function we do initialize
common_rates = intel_dp->common_rates;
so why cant we pass just common_rates to this function instead of intel_dp->common_rates?
Not sure if this optimization will make any big impact but just a thought.

Regards
Manasi 
> >
> > Regards
> > Manasi
> >
> >
> >> -		if (link_rate_index >= 0)
> >> -			min_clock = max_clock = link_rate_index;
> >> +		int index;
> >> +
> >> +		index = intel_dp_find_rate(intel_dp->common_rates,
> >> +					   intel_dp->num_common_rates,
> >> +					   intel_dp->compliance.test_link_rate);
> >> +		if (index >= 0)
> >> +			min_clock = max_clock = index;
> >>  		min_lane_count = max_lane_count = intel_dp->compliance.test_lane_count;
> >>  	}
> >>  	DRM_DEBUG_KMS("DP link computation with max lane count %i "
> >> -- 
> >> 2.1.4
> >> 
> > _______________________________________________
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> > Intel-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center