[Intel-gfx] [PATCH 1/2] drm/i915: Detect eDRAM with the enabled bit only

[Damien Lespiau]

At the moment we compare the whole EDRAM_PRESENT/EDRAMCAP register value
to 1 while EDRAM_PRESENT is only bit 0 (the rest may be used to describe
eDRAM capabilities).

To be more future proof, only look at bit 0 to detect eDRAM presence.

Signed-off-by: Damien Lespiau <damien.lespiau at intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h     | 1 +
 drivers/gpu/drm/i915/intel_uncore.c | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 33b3d0a2..0aeaf7d 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5980,6 +5980,7 @@ enum punit_power_well {
 #define  HSW_IDICR				0x9008
 #define    IDIHASHMSK(x)			(((x) & 0x3f) << 16)
 #define  HSW_EDRAM_PRESENT			0x120010
+#define    EDRAM_ENABLED			0x1
 
 #define GEN6_UCGCTL1				0x9400
 # define GEN6_EU_TCUNIT_CLOCK_GATE_DISABLE		(1 << 16)
diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
index 76b60a3..00c91be 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -328,7 +328,7 @@ static void intel_uncore_ellc_detect(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
 	if ((IS_HASWELL(dev) || IS_BROADWELL(dev)) &&
-	    (__raw_i915_read32(dev_priv, HSW_EDRAM_PRESENT) == 1)) {
+	    (__raw_i915_read32(dev_priv, HSW_EDRAM_PRESENT) & EDRAM_ENABLED)) {
 		/* The docs do not explain exactly how the calculation can be
 		 * made. It is somewhat guessable, but for now, it's always
 		 * 128MB.
-- 
1.8.3.1