drm/i915: load a ring frequency scaling table v3
The ring frequency scaling table tells the PCU to treat certain GPU
frequencies as if they were a given CPU frequency for purposes of
scaling the ring frequency. Normally the PCU will scale the ring
frequency based on the CPU P-state, but with the table present, it will
also take the GPU frequency into account.
The main downside of keeping the ring frequency high while the CPU is
at a low frequency (or asleep altogether) is increased power
consumption. But then if you're keeping your GPU busy, you probably
want the extra performance.
v2:
- add units to debug table header (from Eric)
- use tsc_khz as a fallback if the cpufreq driver doesn't give us a freq
(from Chris)
v3:
- fix comments & debug output
- remove unneeded force wake get/put
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Tested-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 5d5def7..4a446b1 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3434,7 +3434,9 @@
#define GEN6_PCODE_MAILBOX 0x138124
#define GEN6_PCODE_READY (1<<31)
#define GEN6_READ_OC_PARAMS 0xc
-#define GEN6_PCODE_WRITE_MIN_FREQ_TABLE 0x9
+#define GEN6_PCODE_WRITE_MIN_FREQ_TABLE 0x8
+#define GEN6_PCODE_READ_MIN_FREQ_TABLE 0x9
#define GEN6_PCODE_DATA 0x138128
+#define GEN6_PCODE_FREQ_IA_RATIO_SHIFT 8
#endif /* _I915_REG_H_ */