[patch 015/100] drm/i915: Change DCC tiling detection case to cover only mobile parts.

Chris Wright
2009-04-23T07:27:16Z

[-- Attachment #1: drm-i915-change-dcc-tiling-detection-case-to-cover-only-mobile-parts.patch --]
[-- Type: text/plain, Size: 2894 bytes --]

-stable review patch. If anyone has any objections, please let us know.
---------------------

From: Eric Anholt <eric@anholt.net>

upstream commit: 568d9a8f6d4bf81e0672c74573dc02981d31e3ea

Later spec investigation has revealed that every 9xx mobile part has
had this register in this format. Also, no non-mobile parts have been shown
to have this register. So make all mobile use the same code, and all
non-mobile use the hack 965 detection.

Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---
drivers/gpu/drm/i915/i915_gem_tiling.c | 31 +++++++++++++++----------------
1 file changed, 15 insertions(+), 16 deletions(-)

--- a/drivers/gpu/drm/i915/i915_gem_tiling.c
+++ b/drivers/gpu/drm/i915/i915_gem_tiling.c
@@ -96,16 +96,16 @@ i915_gem_detect_bit_6_swizzle(struct drm
*/
swizzle_x = I915_BIT_6_SWIZZLE_NONE;
swizzle_y = I915_BIT_6_SWIZZLE_NONE;
- } else if ((!IS_I965G(dev) && !IS_G33(dev)) || IS_I965GM(dev) ||
- IS_GM45(dev)) {
+ } else if (IS_MOBILE(dev)) {
uint32_t dcc;

- /* On 915-945 and GM965, channel interleave by the CPU is
- * determined by DCC. The CPU will alternate based on bit 6
- * in interleaved mode, and the GPU will then also alternate
- * on bit 6, 9, and 10 for X, but the CPU may also optionally
- * alternate based on bit 17 (XOR not disabled and XOR
- * bit == 17).
+ /* On mobile 9xx chipsets, channel interleave by the CPU is
+ * determined by DCC. For single-channel, neither the CPU
+ * nor the GPU do swizzling. For dual channel interleaved,
+ * the GPU's interleave is bit 9 and 10 for X tiled, and bit
+ * 9 for Y tiled. The CPU's interleave is independent, and
+ * can be based on either bit 11 (haven't seen this yet) or
+ * bit 17 (common).
*/
dcc = I915_READ(DCC);
switch (dcc & DCC_ADDRESSING_MODE_MASK) {
@@ -115,19 +115,18 @@ i915_gem_detect_bit_6_swizzle(struct drm
swizzle_y = I915_BIT_6_SWIZZLE_NONE;
break;
case DCC_ADDRESSING_MODE_DUAL_CHANNEL_INTERLEAVED:
- if (IS_I915G(dev) || IS_I915GM(dev) ||
- dcc & DCC_CHANNEL_XOR_DISABLE) {
+ if (dcc & DCC_CHANNEL_XOR_DISABLE) {
+ /* This is the base swizzling by the GPU for
+ * tiled buffers.
+ */
swizzle_x = I915_BIT_6_SWIZZLE_9_10;
swizzle_y = I915_BIT_6_SWIZZLE_9;
- } else if ((IS_I965GM(dev) || IS_GM45(dev)) &&
- (dcc & DCC_CHANNEL_XOR_BIT_17) == 0) {
- /* GM965/GM45 does either bit 11 or bit 17
- * swizzling.
- */
+ } else if ((dcc & DCC_CHANNEL_XOR_BIT_17) == 0) {
+ /* Bit 11 swizzling by the CPU in addition. */
swizzle_x = I915_BIT_6_SWIZZLE_9_10_11;
swizzle_y = I915_BIT_6_SWIZZLE_9_11;
} else {
- /* Bit 17 or perhaps other swizzling */
+ /* Bit 17 swizzling by the CPU in addition. */
swizzle_x = I915_BIT_6_SWIZZLE_UNKNOWN;
swizzle_y = I915_BIT_6_SWIZZLE_UNKNOWN;
}