1 files changed, 26 insertions, 59 deletions

diff --git a/drivers/gpu/drm/nouveau/nv04_timer.c b/drivers/gpu/drm/nouveau/nv04_timer.c
index 55c9452..1d09ddd 100644
--- a/drivers/gpu/drm/nouveau/nv04_timer.c
+++ b/drivers/gpu/drm/nouveau/nv04_timer.c
@@ -2,80 +2,47 @@
 #include "drm.h"
 #include "nouveau_drv.h"
 #include "nouveau_drm.h"
-#include "nouveau_hw.h"
 
 int
 nv04_timer_init(struct drm_device *dev)
 {
-	struct drm_nouveau_private *dev_priv = dev->dev_private;
-	u32 m, n, d;
-
 	nv_wr32(dev, NV04_PTIMER_INTR_EN_0, 0x00000000);
 	nv_wr32(dev, NV04_PTIMER_INTR_0, 0xFFFFFFFF);
 
-	/* aim for 31.25MHz, which gives us nanosecond timestamps */
-	d = 1000000 / 32;
-
-	/* determine base clock for timer source */
-	if (dev_priv->chipset < 0x40) {
-		n = nouveau_hw_get_clock(dev, PLL_CORE);
-	} else
-	if (dev_priv->chipset == 0x40) {
-		/*XXX: figure this out */
-		n = 0;
-	} else {
-		n = dev_priv->crystal;
-		m = 1;
-		while (n < (d * 2)) {
-			n += (n / m);
-			m++;
-		}
-
-		nv_wr32(dev, 0x009220, m - 1);
-	}
-
-	if (!n) {
-		NV_WARN(dev, "PTIMER: unknown input clock freq\n");
-		if (!nv_rd32(dev, NV04_PTIMER_NUMERATOR) ||
-		    !nv_rd32(dev, NV04_PTIMER_DENOMINATOR)) {
-			nv_wr32(dev, NV04_PTIMER_NUMERATOR, 1);
-			nv_wr32(dev, NV04_PTIMER_DENOMINATOR, 1);
-		}
-		return 0;
-	}
-
-	/* reduce ratio to acceptable values */
-	while (((n % 5) == 0) && ((d % 5) == 0)) {
-		n /= 5;
-		d /= 5;
+	/* Just use the pre-existing values when possible for now; these regs
+	 * are not written in nv (driver writer missed a /4 on the address), and
+	 * writing 8 and 3 to the correct regs breaks the timings on the LVDS
+	 * hardware sequencing microcode.
+	 * A correct solution (involving calculations with the GPU PLL) can
+	 * be done when kernel modesetting lands
+	 */
+	if (!nv_rd32(dev, NV04_PTIMER_NUMERATOR) ||
+				!nv_rd32(dev, NV04_PTIMER_DENOMINATOR)) {
+		nv_wr32(dev, NV04_PTIMER_NUMERATOR, 0x00000008);
+		nv_wr32(dev, NV04_PTIMER_DENOMINATOR, 0x00000003);
 	}
 
-	while (((n % 2) == 0) && ((d % 2) == 0)) {
-		n /= 2;
-		d /= 2;
-	}
-
-	while (n > 0xffff || d > 0xffff) {
-		n >>= 1;
-		d >>= 1;
-	}
-
-	nv_wr32(dev, NV04_PTIMER_NUMERATOR, n);
-	nv_wr32(dev, NV04_PTIMER_DENOMINATOR, d);
 	return 0;
 }
 
-u64
+uint64_t
 nv04_timer_read(struct drm_device *dev)
 {
-	u32 hi, lo;
-
+	uint32_t low;
+	/* From kmmio dumps on nv28 this looks like how the blob does this.
+	 * It reads the high dword twice, before and after.
+	 * The only explanation seems to be that the 64-bit timer counter
+	 * advances between high and low dword reads and may corrupt the
+	 * result. Not confirmed.
+	 */
+	uint32_t high2 = nv_rd32(dev, NV04_PTIMER_TIME_1);
+	uint32_t high1;
 	do {
-		hi = nv_rd32(dev, NV04_PTIMER_TIME_1);
-		lo = nv_rd32(dev, NV04_PTIMER_TIME_0);
-	} while (hi != nv_rd32(dev, NV04_PTIMER_TIME_1));
-
-	return ((u64)hi << 32 | lo);
+		high1 = high2;
+		low = nv_rd32(dev, NV04_PTIMER_TIME_0);
+		high2 = nv_rd32(dev, NV04_PTIMER_TIME_1);
+	} while (high1 != high2);
+	return (((uint64_t)high2) << 32) | (uint64_t)low;
 }
 
 void