On Wed, 2011-11-16 at 16:29 -0800, Keith Packard wrote:
The Ivybridge eDP control register looks like a cross between a Cougarpoint PCH DP control register and a Sandybridge eDP control register.
Your silicon people worry me.
+/* IVB */ +#define EDP_LINK_TRAIN_400MV_0DB_IVB (0x24 <<22) +#define EDP_LINK_TRAIN_400MV_3_5DB_IVB (0x2a <<22) +#define EDP_LINK_TRAIN_400MV_6DB_IVB (0x2f <<22) +#define EDP_LINK_TRAIN_600MV_0DB_IVB (0x30 <<22) +#define EDP_LINK_TRAIN_600MV_3_5DB_IVB (0x36 <<22) +#define EDP_LINK_TRAIN_800MV_0DB_IVB (0x38 <<22) +#define EDP_LINK_TRAIN_800MV_3_5DB_IVB (0x33 <<22)
+/* legacy values */ +#define EDP_LINK_TRAIN_500MV_0DB_IVB (0x00 <<22) +#define EDP_LINK_TRAIN_1000MV_0DB_IVB (0x20 <<22) +#define EDP_LINK_TRAIN_500MV_3_5DB_IVB (0x02 <<22) +#define EDP_LINK_TRAIN_1000MV_3_5DB_IVB (0x22 <<22) +#define EDP_LINK_TRAIN_1000MV_6DB_IVB (0x23 <<22)
I don't even. Unless you're looking at some other version of the DP spec than me, I was pretty sure those weren't legal voltage values. And 3.5dB preemph on 1000mV gives you 1500mV at the peak, which is definitely outside the spec.
- ajax