From: Ville Syrjälä <[email protected]> Some systems (eg. LNL Lenovo Thinkapd X1 Carbon) declare semi-bogus non-monotonic WM latency values: WM0 latency not provided WM1 latency 100 usec WM2 latency 100 usec WM3 latency 100 usec WM4 latency 93 usec WM5 latency 100 usec
Apparently Windows just papers over the issue by bumping the latencies for the higher watermark levels to make them monotonic again. Do the same. Cc: Luca Coelho <[email protected]> Signed-off-by: Ville Syrjälä <[email protected]> --- drivers/gpu/drm/i915/display/skl_watermark.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/gpu/drm/i915/display/skl_watermark.c b/drivers/gpu/drm/i915/display/skl_watermark.c index d83772c6ea9a..2a40c135cb96 100644 --- a/drivers/gpu/drm/i915/display/skl_watermark.c +++ b/drivers/gpu/drm/i915/display/skl_watermark.c @@ -3236,6 +3236,19 @@ static void sanitize_wm_latency(struct intel_display *display) wm[level] = 0; } +static void make_wm_latency_monotonic(struct intel_display *display) +{ + u16 *wm = display->wm.skl_latency; + int level, num_levels = display->wm.num_levels; + + for (level = 1; level < num_levels; level++) { + if (wm[level] == 0) + break; + + wm[level] = max(wm[level], wm[level-1]); + } +} + static void adjust_wm_latency(struct intel_display *display) { @@ -3246,6 +3259,8 @@ adjust_wm_latency(struct intel_display *display) sanitize_wm_latency(display); + make_wm_latency_monotonic(display); + /* * WaWmMemoryReadLatency * -- 2.49.1
