[coreboot-gerrit] Change in coreboot[master]: nb/intel/sandybridge/gma.c: Add Kconfig options for RC6 and RC6p

[Evgeny Zinoviev (Code Review)]

Evgeny Zinoviev has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/42450 )

Change subject: nb/intel/sandybridge/gma.c: Add Kconfig options for RC6 and RC6p
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nb/intel/sandybridge/gma.c: Add Kconfig options for RC6 and RC6p

Add Kconfig options to enable or disable RC6 and RC6p.

TODO

- Not sure if it's OK to allow to enable RC6p alone without RC6p.
  If yes then I'll update the patch.

Change-Id: I6166d04b3bcb7a55f1d03c397d87eaa62c64b48b
Signed-off-by: Evgeny Zinoviev 
---
M src/northbridge/intel/sandybridge/Kconfig
M src/northbridge/intel/sandybridge/gma.c
2 files changed, 26 insertions(+), 10 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/50/42450/1

diff --git a/src/northbridge/intel/sandybridge/Kconfig b/src/northbridge/intel/sandybridge/Kconfig
index ef6dc3d..95f1deb 100644
--- a/src/northbridge/intel/sandybridge/Kconfig
+++ b/src/northbridge/intel/sandybridge/Kconfig
@@ -129,4 +129,18 @@
 config INTEL_GMA_BCLV_OFFSET
    default 0x48254

+config ENABLE_RC6
+	bool "Enable RC6 (Render Standby)"
+	default y
+	help
+	  Select this if you want to enable RC6 (Render Standby).
+
+config ENABLE_RC6P
+	depends on ENABLE_RC6
+	bool "Enable RC6p (Deep Render Standby)"
+	default n
+	help
+	  Select this if you want to enable RC6p (Deep Render Standby).
+	  This should only be selected on Ivy Bridge.
+
 endif
diff --git a/src/northbridge/intel/sandybridge/gma.c b/src/northbridge/intel/sandybridge/gma.c
index 8fe2de8..d976530 100644
--- a/src/northbridge/intel/sandybridge/gma.c
+++ b/src/northbridge/intel/sandybridge/gma.c
@@ -450,15 +450,15 @@
    gtt_write(0xa06c, 0x000493e0); /* RP Down EI */
    gtt_write(0xa070, 0x0000000a); /* RP Idle Hysteresis */

-	/*
-	 * 10a: Enable Render Standby (RC6)
-	 *
-	 * IvyBridge should also support DeepRenderStandby.
-	 *
-	 * Unfortunately it does not work reliably on all SKUs so
-	 * disable it here and it can be enabled by the kernel.
-	 */
-	gtt_write(0xa090, 0x88040000); /* HW RC Control */
+	/* 10a: Enable Render Standby (RC6) and Deep Render Standby (RC6p) */
+	reg32 = 0;
+#if CONFIG(ENABLE_RC6)
+	reg32 |= 0x88040000;
+#if CONFIG(ENABLE_RC6P)
+	reg32 |= 0x00020000;
+#endif
+#endif
+	gtt_write(0xa090, reg32);

/* 11: Normal Frequency Request */
    /* RPNFREQ_VAL comes from MCHBAR 0x5998 23:16 */
@@ -516,8 +516,10 @@
    		gtt_write(0xa188, gtt_read(0xa188) | 1);
    }

-	/* 16: SW RC Control */
+	/* 16: SW RC state: RC6 deepest */
+#if CONFIG(ENABLE_RC6) || CONFIG(ENABLE_RC6P)
    gtt_write(0xa094, 0x00060000);
+#endif

/* Setup Digital Port Hotplug */
    reg32 = gtt_read(0xc4030);