[RFC PATCH] Revert "drm/i915: Disable compression tricks on JSL"

[Sebastian Brzezinka]

This reverts commit 0ddae025ab6cefa9aba757da3cd1d27908d70b0e.

According to bspec 14181, CACHE_MODE_0 is a register that's under userspace
control, and DISABLE_REPACKING_FOR_COMPRESSION workaround should be already
in all recent Mesa releases. So, there is no need to include it in kernel.

Also, this workaround·sporadically fails to load:
```
ERROR GT0: engine workaround lost on application! (reg[7000]=0x0,
relevant bits were 0x0 vs expected 0x8000)
```

Signed-off-by: Sebastian Brzezinka <sebastian.brzezinka at intel.com>
---
 drivers/gpu/drm/i915/gt/intel_gt_regs.h     | 1 -
 drivers/gpu/drm/i915/gt/intel_workarounds.c | 9 ---------
 2 files changed, 10 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
index 7421ed18d8d1..52ddfa9f3ad3 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
@@ -440,7 +440,6 @@
 #define XEHPG_INSTDONE_GEOM_SVG			MCR_REG(0x666c)
 
 #define CACHE_MODE_0_GEN7			_MMIO(0x7000) /* IVB+ */
-#define   DISABLE_REPACKING_FOR_COMPRESSION	REG_BIT(15) /* jsl+ */
 #define   RC_OP_FLUSH_ENABLE			(1 << 0)
 #define   HIZ_RAW_STALL_OPT_DISABLE		(1 << 2)
 #define CACHE_MODE_1				_MMIO(0x7004) /* IVB+ */
diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
index 116683ebe074..51839f270d57 100644
--- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
@@ -2306,15 +2306,6 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal)
 			     GEN8_RC_SEMA_IDLE_MSG_DISABLE);
 	}
 
-	if (IS_JASPERLAKE(i915) || IS_ELKHARTLAKE(i915)) {
-		/*
-		 * "Disable Repacking for Compression (masked R/W access)
-		 *  before rendering compressed surfaces for display."
-		 */
-		wa_masked_en(wal, CACHE_MODE_0_GEN7,
-			     DISABLE_REPACKING_FOR_COMPRESSION);
-	}
-
 	if (GRAPHICS_VER(i915) == 11) {
 		/* This is not an Wa. Enable for better image quality */
 		wa_masked_en(wal,
-- 
2.34.1