Faster feedback to errors is always better. This is inspired by the
addition to WARN_ONs to mask/enable helpers for registers to make sure
callers have the arguments ordered correctly: Pretty much always the
arguments are static.
We use WARN_ON(1) a lot in default switch statements though where we
should always handle all cases. So add a new macro specifically for
that.
The idea to use __builtin_constant_p is from Chris Wilson.
v2: Use the ({}) gcc-ism to avoid the static inline, suggested by
Dave. My first attempt used __cond as the temp var, which is the same
used by BUILD_BUG_ON, but with inverted sense. Hilarity ensued, so
sprinkle i915 into the name.
Also use a temporary variable to only evaluate the condition once,
suggested by Damien.
v3: It's crazy but apparently 32bit gcc can't compile out the
BUILD_BUG_ON in a lot of cases and just falls over. I have no idea
why, but until clue grows just disable this nifty idea on 32bit
builds. Reported by 0-day builder.
v4: Got it all wrong, apparently its the gcc version. We need 4.9+.
Now reported by Imre.
v5: Chris suggested to add the case to MISSING_CASE for speedier
debug.
Cc: Imre Deak <imre.d...@intel.com>
Cc: Damien Lespiau <damien.lesp...@intel.com>
Cc: Chris Wilson <ch...@chris-wilson.co.uk>
Cc: Jani Nikula <jani.nik...@linux.intel.com>
Cc: Dave Gordon <david.s.gor...@intel.com>
Signed-off-by: Daniel Vetter <daniel.vet...@intel.com>
---
drivers/gpu/drm/i915/i915_debugfs.c | 2 +-
drivers/gpu/drm/i915/i915_drv.h | 14 +++++++++++++-
drivers/gpu/drm/i915/i915_gem_gtt.c | 6 +++---
drivers/gpu/drm/i915/intel_display.c | 4 ++--
drivers/gpu/drm/i915/intel_uncore.c | 4 ++--
5 files changed, 21 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c
b/drivers/gpu/drm/i915/i915_debugfs.c
index 165a38f36009..479e0c119111 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2347,7 +2347,7 @@ static const char *power_domain_str(enum
intel_display_power_domain domain)
case POWER_DOMAIN_INIT:
return "INIT";
default:
- WARN_ON(1);
+ MISSING_CASE(domain);
return "?";
}
}
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index c74dc946cbf6..aeb1ef3ef2b6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -58,7 +58,19 @@
#define DRIVER_DATE "20141205"
#undef WARN_ON
-#define WARN_ON(x) WARN(x, "WARN_ON(" #x ")")
+/* Only 4.9+ gcc can compile away the BUILD_BUG_ON correctly. */
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 9)
+#define WARN_ON(x) ({ \
+ bool __i915_warn_cond = (x); \
+ if (__builtin_constant_p(__i915_warn_cond)) \
+ BUILD_BUG_ON(__i915_warn_cond); \
+ WARN(__i915_warn_cond, "WARN_ON(" #x ")"); })
+#else
+#define WARN_ON(x) WARN((x), "WARN_ON(" #x ")")
+#endif
+
+#define MISSING_CASE(x) WARN(1, "Missing switch case (%lu) in %s\n", \
+ (long) (x), __func__);
enum pipe {
INVALID_PIPE = -1,
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c
b/drivers/gpu/drm/i915/i915_gem_gtt.c
index ac03a382000b..ce4e46c443a1 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -132,7 +132,7 @@ static gen6_gtt_pte_t snb_pte_encode(dma_addr_t addr,
pte |= GEN6_PTE_UNCACHED;
break;
default:
- WARN_ON(1);
+ MISSING_CASE(level);
}
return pte;
@@ -156,7 +156,7 @@ static gen6_gtt_pte_t ivb_pte_encode(dma_addr_t addr,
pte |= GEN6_PTE_UNCACHED;
break;
default:
- WARN_ON(1);
+ MISSING_CASE(level);
}
return pte;
@@ -1146,7 +1146,7 @@ int i915_ppgtt_init_hw(struct drm_device *dev)
else if (INTEL_INFO(dev)->gen >= 8)
gen8_ppgtt_enable(dev);
else
- WARN_ON(1);
+ MISSING_CASE(INTEL_INFO(dev)->gen);
if (ppgtt) {
for_each_ring(ring, dev_priv, i) {
diff --git a/drivers/gpu/drm/i915/intel_display.c
b/drivers/gpu/drm/i915/intel_display.c
index 841af6c1f50b..878c4857ff49 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4847,7 +4847,7 @@ static void cherryview_set_cdclk(struct drm_device *dev,
int cdclk)
cmd = 0;
break;
default:
- WARN_ON(1);
+ MISSING_CASE(cdclk);
return;
}
@@ -8224,7 +8224,7 @@ static void i9xx_update_cursor(struct drm_crtc *crtc, u32
base)
cntl |= CURSOR_MODE_256_ARGB_AX;
break;
default:
- WARN_ON(1);
+ MISSING_CASE(intel_crtc->cursor_width);
return;
}
cntl |= pipe << 28; /* Connect to correct pipe */
diff --git a/drivers/gpu/drm/i915/intel_uncore.c
b/drivers/gpu/drm/i915/intel_uncore.c
index 46de8d75b4bf..883d2febb705 100644
--- a/drivers/gpu/drm/i915/intel_uncore.c
+++ b/drivers/gpu/drm/i915/intel_uncore.c
@@ -1202,7 +1202,7 @@ void intel_uncore_init(struct drm_device *dev)
switch (INTEL_INFO(dev)->gen) {
default:
- WARN_ON(1);
+ MISSING_CASE(INTEL_INFO(dev)->gen);
return;
case 9:
ASSIGN_WRITE_MMIO_VFUNCS(gen9);
@@ -1300,7 +1300,7 @@ int i915_reg_read_ioctl(struct drm_device *dev,
reg->val = I915_READ8(reg->offset);
break;
default:
- WARN_ON(1);
+ MISSING_CASE(entry->size);
ret = -EINVAL;
goto out;
}
--
2.1.3
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