[Intel-gfx] [PATCH 17/19] drm/i915: Fix HSW parity test

[Rodrigo Vivi]

From: Ben Widawsky <benjamin.widawsky at intel.com>

Haswell changed the log registers to be WO, so we can no longer read
them to determine the programming (which sucks, see later note). For
now, simply use the cached value, and hope HW doesn't screw us over.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=57441
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
Tested-by: shui yangwei <yangweix.shui at intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at gmail.com>
---
 drivers/gpu/drm/i915/i915_sysfs.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index 70de7a9..491aba6 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -129,6 +129,19 @@ i915_l3_read(struct file *filp, struct kobject *kobj,
 	if (ret)
 		return ret;
 
+	if (IS_HASWELL(drm_dev)) {
+		int last = min_t(int, GEN7_L3LOG_SIZE, count + offset);
+		if ((!dev_priv->l3_parity.remap_info))
+			memset(buf + offset, 0, last - offset);
+		else
+			memcpy(buf + offset,
+			       dev_priv->l3_parity.remap_info + (offset/4),
+			       last - offset);
+
+		i = last;
+		goto out;
+	}
+
 	misccpctl = I915_READ(GEN7_MISCCPCTL);
 	I915_WRITE(GEN7_MISCCPCTL, misccpctl & ~GEN7_DOP_CLOCK_GATE_ENABLE);
 
@@ -137,6 +150,7 @@ i915_l3_read(struct file *filp, struct kobject *kobj,
 
 	I915_WRITE(GEN7_MISCCPCTL, misccpctl);
 
+out:
 	mutex_unlock(&drm_dev->struct_mutex);
 
 	return i - offset;
-- 
1.8.1.4