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Commit 9c2f7a9d authored by Kumar, Mahesh's avatar Kumar, Mahesh Committed by Matt Roper
Browse files

drm/i915/skl+: calculate plane pixel rate (v4) 



Don't use pipe pixel rate for plane pixel rate. Calculate plane pixel according
to formula

adjusted plane_pixel_rate = adjusted pipe_pixel_rate * downscale ammount

downscale amount = max[1, src_h/dst_h] * max[1, src_w/dst_w]
if 90/270 rotation use rotated width & height

v2: use intel_plane_state->visible instead of (fb == NULL) as per Matt's
    comment.

v3 (by Matt):
 - Keep downscale amount in 16.16 fixed point rather than converting to
   decimal fixed point.
 - Store adjusted plane pixel rate in plane state instead of the plane
   parameters structure that we no longer use.

v4 (by Matt):
 - Significant rebasing onto latest atomic watermark work
 - Don't bother storing plane pixel rate in state; just calculate it
   right before the calls that make use of it.
 - Fix downscale calculations to actually use width values when
   computing downscale_w rather than copy/pasted height values.

Cc: matthew.d.roper@intel.com
Signed-off-by: default avatarKumar, Mahesh <mahesh1.kumar@intel.com>
Signed-off-by: default avatarMatt Roper <matthew.d.roper@intel.com>
Reviewed-by: default avatarKumar Mahesh <mahesh1.kumar@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1463439121-28974-4-git-send-email-matthew.d.roper@intel.com
parent cbcfd14b

drivers/gpu/drm/i915/intel_pm.c

+70 −3
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
 */



#include <linux/cpufreq.h>

#include <drm/drm_plane_helper.h>

#include "i915_drv.h"

#include "intel_drv.h"

#include "../../../platform/x86/intel_ips.h"
@@ -2949,6 +2950,46 @@ void skl_ddb_get_hw_state(struct drm_i915_private *dev_priv, 
	}

}



/*

 * Determines the downscale amount of a plane for the purposes of watermark calculations.

 * The bspec defines downscale amount as:

 *

 * """

 * Horizontal down scale amount = maximum[1, Horizontal source size /

 *                                           Horizontal destination size]

 * Vertical down scale amount = maximum[1, Vertical source size /

 *                                         Vertical destination size]

 * Total down scale amount = Horizontal down scale amount *

 *                           Vertical down scale amount

 * """

 *

 * Return value is provided in 16.16 fixed point form to retain fractional part.

 * Caller should take care of dividing & rounding off the value.

 */

static uint32_t

skl_plane_downscale_amount(const struct intel_plane_state *pstate)

{

	uint32_t downscale_h, downscale_w;

	uint32_t src_w, src_h, dst_w, dst_h;



	if (WARN_ON(!pstate->visible))

		return DRM_PLANE_HELPER_NO_SCALING;



	/* n.b., src is 16.16 fixed point, dst is whole integer */

	src_w = drm_rect_width(&pstate->src);

	src_h = drm_rect_height(&pstate->src);

	dst_w = drm_rect_width(&pstate->dst);

	dst_h = drm_rect_height(&pstate->dst);

	if (intel_rotation_90_or_270(pstate->base.rotation))

		swap(dst_w, dst_h);



	downscale_h = max(src_h / dst_h, (uint32_t)DRM_PLANE_HELPER_NO_SCALING);

	downscale_w = max(src_w / dst_w, (uint32_t)DRM_PLANE_HELPER_NO_SCALING);



	/* Provide result in 16.16 fixed point */

	return (uint64_t)downscale_w * downscale_h >> 16;

}



static unsigned int

skl_plane_relative_data_rate(const struct intel_crtc_state *cstate,

			     const struct drm_plane_state *pstate,
@@ -3285,6 +3326,30 @@ static uint32_t skl_wm_method2(uint32_t pixel_rate, uint32_t pipe_htotal, 
	return ret;

}



static uint32_t skl_adjusted_plane_pixel_rate(const struct intel_crtc_state *cstate,

					      struct intel_plane_state *pstate)

{

	uint64_t adjusted_pixel_rate;

	uint64_t downscale_amount;

	uint64_t pixel_rate;



	/* Shouldn't reach here on disabled planes... */

	if (WARN_ON(!pstate->visible))

		return 0;



	/*

	 * Adjusted plane pixel rate is just the pipe's adjusted pixel rate

	 * with additional adjustments for plane-specific scaling.

	 */

	adjusted_pixel_rate = skl_pipe_pixel_rate(cstate);

	downscale_amount = skl_plane_downscale_amount(pstate);



	pixel_rate = adjusted_pixel_rate * downscale_amount >> 16;

	WARN_ON(pixel_rate != clamp_t(uint32_t, pixel_rate, 0, ~0));



	return pixel_rate;

}



static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv,

				struct intel_crtc_state *cstate,

				struct intel_plane_state *intel_pstate,
@@ -3303,6 +3368,7 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv, 
	uint32_t selected_result;

	uint8_t cpp;

	uint32_t width = 0, height = 0;

	uint32_t plane_pixel_rate;



	if (latency == 0 || !cstate->base.active || !intel_pstate->visible) {

		*enabled = false;
@@ -3316,9 +3382,10 @@ static int skl_compute_plane_wm(const struct drm_i915_private *dev_priv, 
		swap(width, height);



	cpp = drm_format_plane_cpp(fb->pixel_format, 0);

	method1 = skl_wm_method1(skl_pipe_pixel_rate(cstate),

				 cpp, latency);

	method2 = skl_wm_method2(skl_pipe_pixel_rate(cstate),

	plane_pixel_rate = skl_adjusted_plane_pixel_rate(cstate, intel_pstate);



	method1 = skl_wm_method1(plane_pixel_rate, cpp, latency);

	method2 = skl_wm_method2(plane_pixel_rate,

				 cstate->base.adjusted_mode.crtc_htotal,

				 width,

				 cpp,