From f360132626b11d0dc60814033873ca0e3111677c Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Wed, 22 Jul 2009 12:54:59 -0700 Subject: drm/i915: fix 845G FIFO size & burst length I had one report of flicker due to FIFO underruns on 845G. Scott was kind enough to test a few patches and report success with this one. Looks like 845G measures FIFO size slightly differently than other chips, and we were also clobbering the FIFO burst length. Fixing both of those issues gives him a healthy machine again. Note that we still only adjust plane A's watermark in the 830/845 case. If someone is willing to test we could support a bigger variety of dual-head 830/845 configurations with a bit more code. Fixes fdo bug #19304 (again). Reported-by: Scott Hansen Tested-by: Scott Hansen Signed-off-by: Jesse Barnes Signed-off-by: Eric Anholt --- drivers/gpu/drm/i915/intel_display.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'drivers/gpu') diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index a9f1307d32d..1da7b0b9ed3 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -2026,6 +2026,9 @@ static int intel_get_fifo_size(struct drm_device *dev, int plane) size = ((dsparb >> DSPARB_BEND_SHIFT) & 0x1ff) - (dsparb & 0x1ff); size >>= 1; /* Convert to cachelines */ + } else if (IS_845G(dev)) { + size = dsparb & 0x7f; + size >>= 2; /* Convert to cachelines */ } else { size = dsparb & 0x7f; size >>= 1; /* Convert to cachelines */ @@ -2125,14 +2128,16 @@ static void i830_update_wm(struct drm_device *dev, int planea_clock, int pixel_size) { struct drm_i915_private *dev_priv = dev->dev_private; - uint32_t fwater_lo = I915_READ(FW_BLC) & MM_FIFO_WATERMARK; + uint32_t fwater_lo = I915_READ(FW_BLC) & ~0xfff; int planea_wm; i830_wm_info.fifo_size = intel_get_fifo_size(dev, 0); planea_wm = intel_calculate_wm(planea_clock, &i830_wm_info, pixel_size, latency_ns); - fwater_lo = fwater_lo | planea_wm; + fwater_lo |= (3<<8) | planea_wm; + + DRM_DEBUG("Setting FIFO watermarks - A: %d\n", planea_wm); I915_WRITE(FW_BLC, fwater_lo); } -- cgit v1.2.3-70-g09d2