diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2011-01-08 09:02:21 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2011-01-11 20:44:54 +0000 |
| commit | db66e37d239b45f36a3f6495cf4ec49391b2c089 (patch) | |
| tree | d16899c361fb77e7732eb603835cb95c3af49421 /drivers | |
| parent | 882417851a0f2e09e110038a13e88e9b5a100800 (diff) | |
drm/i915: Include TLB miss overhead for computing WM
The docs recommend that if 8 display lines fit inside the FIFO buffer,
then the number of watermark entries should be increased to hide the
latency of filling the rest of the FIFO buffer.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_display.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 1190efa390b..25d96889d7d 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -3425,8 +3425,9 @@ static bool ironlake_compute_wm0(struct drm_device *dev, int *cursor_wm) { struct drm_crtc *crtc; - int htotal, hdisplay, clock, pixel_size = 0; - int line_time_us, line_count, entries; + int htotal, hdisplay, clock, pixel_size; + int line_time_us, line_count; + int entries, tlb_miss; crtc = intel_get_crtc_for_pipe(dev, pipe); if (crtc->fb == NULL || !crtc->enabled) @@ -3439,6 +3440,9 @@ static bool ironlake_compute_wm0(struct drm_device *dev, /* Use the small buffer method to calculate plane watermark */ entries = ((clock * pixel_size / 1000) * display_latency_ns) / 1000; + tlb_miss = display->fifo_size*display->cacheline_size - hdisplay * 8; + if (tlb_miss > 0) + entries += tlb_miss; entries = DIV_ROUND_UP(entries, display->cacheline_size); *plane_wm = entries + display->guard_size; if (*plane_wm > (int)display->max_wm) @@ -3448,6 +3452,9 @@ static bool ironlake_compute_wm0(struct drm_device *dev, line_time_us = ((htotal * 1000) / clock); line_count = (cursor_latency_ns / line_time_us + 1000) / 1000; entries = line_count * 64 * pixel_size; + tlb_miss = cursor->fifo_size*cursor->cacheline_size - hdisplay * 8; + if (tlb_miss > 0) + entries += tlb_miss; entries = DIV_ROUND_UP(entries, cursor->cacheline_size); *cursor_wm = entries + cursor->guard_size; if (*cursor_wm > (int)cursor->max_wm) |