Commit 0f95ff85 authored by Ville Syrjälä's avatar Ville Syrjälä

drm/i915: Refactor the g4x TLB miss w/a to a helper

Pull the g4x TLB miss w/a calculation into a small helper.
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170421181432.15216-10-ville.syrjala@linux.intel.comReviewed-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
parent 624a0ac3
...@@ -799,6 +799,23 @@ static void pineview_update_wm(struct intel_crtc *unused_crtc) ...@@ -799,6 +799,23 @@ static void pineview_update_wm(struct intel_crtc *unused_crtc)
} }
} }
/*
* Documentation says:
* "If the line size is small, the TLB fetches can get in the way of the
* data fetches, causing some lag in the pixel data return which is not
* accounted for in the above formulas. The following adjustment only
* needs to be applied if eight whole lines fit in the buffer at once.
* The WM is adjusted upwards by the difference between the FIFO size
* and the size of 8 whole lines. This adjustment is always performed
* in the actual pixel depth regardless of whether FBC is enabled or not."
*/
static int g4x_tlb_miss_wa(int fifo_size, int width, int cpp)
{
int tlb_miss = fifo_size * 64 - width * cpp * 8;
return max(0, tlb_miss);
}
static bool g4x_compute_wm0(struct drm_i915_private *dev_priv, static bool g4x_compute_wm0(struct drm_i915_private *dev_priv,
int plane, int plane,
const struct intel_watermark_params *display, const struct intel_watermark_params *display,
...@@ -813,7 +830,7 @@ static bool g4x_compute_wm0(struct drm_i915_private *dev_priv, ...@@ -813,7 +830,7 @@ static bool g4x_compute_wm0(struct drm_i915_private *dev_priv,
const struct drm_framebuffer *fb; const struct drm_framebuffer *fb;
int htotal, plane_width, cursor_width, clock, cpp; int htotal, plane_width, cursor_width, clock, cpp;
int line_time_us, line_count; int line_time_us, line_count;
int entries, tlb_miss; int entries;
crtc = intel_get_crtc_for_plane(dev_priv, plane); crtc = intel_get_crtc_for_plane(dev_priv, plane);
if (!intel_crtc_active(crtc)) { if (!intel_crtc_active(crtc)) {
...@@ -832,9 +849,7 @@ static bool g4x_compute_wm0(struct drm_i915_private *dev_priv, ...@@ -832,9 +849,7 @@ static bool g4x_compute_wm0(struct drm_i915_private *dev_priv,
/* Use the small buffer method to calculate plane watermark */ /* Use the small buffer method to calculate plane watermark */
entries = ((clock * cpp / 1000) * display_latency_ns) / 1000; entries = ((clock * cpp / 1000) * display_latency_ns) / 1000;
tlb_miss = display->fifo_size*display->cacheline_size - plane_width * cpp * 8; entries += g4x_tlb_miss_wa(display->fifo_size, plane_width, cpp);
if (tlb_miss > 0)
entries += tlb_miss;
entries = DIV_ROUND_UP(entries, display->cacheline_size); entries = DIV_ROUND_UP(entries, display->cacheline_size);
*plane_wm = entries + display->guard_size; *plane_wm = entries + display->guard_size;
if (*plane_wm > (int)display->max_wm) if (*plane_wm > (int)display->max_wm)
...@@ -844,9 +859,7 @@ static bool g4x_compute_wm0(struct drm_i915_private *dev_priv, ...@@ -844,9 +859,7 @@ static bool g4x_compute_wm0(struct drm_i915_private *dev_priv,
line_time_us = max(htotal * 1000 / clock, 1); line_time_us = max(htotal * 1000 / clock, 1);
line_count = (cursor_latency_ns / line_time_us + 1000) / 1000; line_count = (cursor_latency_ns / line_time_us + 1000) / 1000;
entries = line_count * cursor_width * 4; entries = line_count * cursor_width * 4;
tlb_miss = cursor->fifo_size*cursor->cacheline_size - cursor_width * 4 * 8; entries += g4x_tlb_miss_wa(cursor->fifo_size, cursor_width, 4);
if (tlb_miss > 0)
entries += tlb_miss;
entries = DIV_ROUND_UP(entries, cursor->cacheline_size); entries = DIV_ROUND_UP(entries, cursor->cacheline_size);
*cursor_wm = entries + cursor->guard_size; *cursor_wm = entries + cursor->guard_size;
if (*cursor_wm > (int)cursor->max_wm) if (*cursor_wm > (int)cursor->max_wm)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment