drm/i915: Always calculate 8xx WM values based on a 32-bpp framebuffer
The specs for gen2 say that the watermark values "should always be set
assuming a 32bpp display mode, even though the display mode may be 15 or
16 bpp."
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 8f156161..0cbc0e6 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -1468,9 +1468,12 @@
fifo_size = dev_priv->display.get_fifo_size(dev, 0);
crtc = intel_get_crtc_for_plane(dev, 0);
if (crtc->enabled && crtc->fb) {
+ int cpp = crtc->fb->bits_per_pixel / 8;
+ if (IS_GEN2(dev))
+ cpp = 4;
+
planea_wm = intel_calculate_wm(crtc->mode.clock,
- wm_info, fifo_size,
- crtc->fb->bits_per_pixel / 8,
+ wm_info, fifo_size, cpp,
latency_ns);
enabled = crtc;
} else
@@ -1479,9 +1482,12 @@
fifo_size = dev_priv->display.get_fifo_size(dev, 1);
crtc = intel_get_crtc_for_plane(dev, 1);
if (crtc->enabled && crtc->fb) {
+ int cpp = crtc->fb->bits_per_pixel / 8;
+ if (IS_GEN2(dev))
+ cpp = 4;
+
planeb_wm = intel_calculate_wm(crtc->mode.clock,
- wm_info, fifo_size,
- crtc->fb->bits_per_pixel / 8,
+ wm_info, fifo_size, cpp,
latency_ns);
if (enabled == NULL)
enabled = crtc;
@@ -1571,8 +1577,7 @@
planea_wm = intel_calculate_wm(crtc->mode.clock, &i830_wm_info,
dev_priv->display.get_fifo_size(dev, 0),
- crtc->fb->bits_per_pixel / 8,
- latency_ns);
+ 4, latency_ns);
fwater_lo = I915_READ(FW_BLC) & ~0xfff;
fwater_lo |= (3<<8) | planea_wm;