drm/i915: Make workaround verification *optional*

Sometimes the HW doesn't even play fair, and completely forgets about
register writes. Skip verifying known troublemakers.

References: https://bugs.freedesktop.org/show_bug.cgi?id=108954
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190417075657.19456-4-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/intel_workarounds.c b/drivers/gpu/drm/i915/intel_workarounds.c
index 89e2c60..b3cbed1 100644 (file)
--- a/drivers/gpu/drm/i915/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/intel_workarounds.c
@@ -122,6 +122,7 @@ static void _wa_add(struct i915_wa_list *wal, const struct i915_wa *wa)
                        wal->wa_count++;
                        wa_->val |= wa->val;
                        wa_->mask |= wa->mask;
+                       wa_->read |= wa->read;
                        return;
                }
        }
@@ -146,9 +147,10 @@ wa_write_masked_or(struct i915_wa_list *wal, i915_reg_t reg, u32 mask,
                   u32 val)
 {
        struct i915_wa wa = {
-               .reg = reg,
+               .reg  = reg,
                .mask = mask,
-               .val = val
+               .val  = val,
+               .read = mask,
        };
 
        _wa_add(wal, &wa);
@@ -172,6 +174,19 @@ wa_write_or(struct i915_wa_list *wal, i915_reg_t reg, u32 val)
        wa_write_masked_or(wal, reg, val, val);
 }
 
+static void
+ignore_wa_write_or(struct i915_wa_list *wal, i915_reg_t reg, u32 mask, u32 val)
+{
+       struct i915_wa wa = {
+               .reg  = reg,
+               .mask = mask,
+               .val  = val,
+               /* Bonkers HW, skip verifying */
+       };
+
+       _wa_add(wal, &wa);
+}
+
 #define WA_SET_BIT_MASKED(addr, mask) \
        wa_write_masked_or(wal, (addr), (mask), _MASKED_BIT_ENABLE(mask))
 
@@ -916,10 +931,11 @@ wal_get_fw_for_rmw(struct intel_uncore *uncore, const struct i915_wa_list *wal)
 static bool
 wa_verify(const struct i915_wa *wa, u32 cur, const char *name, const char *from)
 {
-       if ((cur ^ wa->val) & wa->mask) {
+       if ((cur ^ wa->val) & wa->read) {
                DRM_ERROR("%s workaround lost on %s! (%x=%x/%x, expected %x, mask=%x)\n",
-                         name, from, i915_mmio_reg_offset(wa->reg), cur,
-                         cur & wa->mask, wa->val, wa->mask);
+                         name, from, i915_mmio_reg_offset(wa->reg),
+                         cur, cur & wa->read,
+                         wa->val, wa->mask);
 
                return false;
        }
@@ -1122,9 +1138,10 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal)
                             _3D_CHICKEN3_AA_LINE_QUALITY_FIX_ENABLE);
 
                /* WaPipelineFlushCoherentLines:icl */
-               wa_write_or(wal,
-                           GEN8_L3SQCREG4,
-                           GEN8_LQSC_FLUSH_COHERENT_LINES);
+               ignore_wa_write_or(wal,
+                                  GEN8_L3SQCREG4,
+                                  GEN8_LQSC_FLUSH_COHERENT_LINES,
+                                  GEN8_LQSC_FLUSH_COHERENT_LINES);
 
                /*
                 * Wa_1405543622:icl
@@ -1151,9 +1168,10 @@ rcs_engine_wa_init(struct intel_engine_cs *engine, struct i915_wa_list *wal)
                 * Wa_1405733216:icl
                 * Formerly known as WaDisableCleanEvicts
                 */
-               wa_write_or(wal,
-                           GEN8_L3SQCREG4,
-                           GEN11_LQSC_CLEAN_EVICT_DISABLE);
+               ignore_wa_write_or(wal,
+                                  GEN8_L3SQCREG4,
+                                  GEN11_LQSC_CLEAN_EVICT_DISABLE,
+                                  GEN11_LQSC_CLEAN_EVICT_DISABLE);
 
                /* WaForwardProgressSoftReset:icl */
                wa_write_or(wal,

diff --git a/drivers/gpu/drm/i915/intel_workarounds_types.h b/drivers/gpu/drm/i915/intel_workarounds_types.h
index 30918da..42ac1fb 100644 (file)
--- a/drivers/gpu/drm/i915/intel_workarounds_types.h
+++ b/drivers/gpu/drm/i915/intel_workarounds_types.h
@@ -12,9 +12,10 @@
 #include "i915_reg.h"
 
 struct i915_wa {
-       i915_reg_t        reg;
-       u32               mask;
-       u32               val;
+       i915_reg_t      reg;
+       u32             mask;
+       u32             val;
+       u32             read;
 };
 
 struct i915_wa_list {