[PATCH] drm/i915: Fix clang -Wimplicit-fallthrough in intel_async_flip_check_hw()

From: Nathan Chancellor <nathan@kernel.org>
To: jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com,
	 rodrigo.vivi@intel.com, tvrtko.ursulin@linux.intel.com
Cc: kernel test robot <lkp@intel.com>,
	trix@redhat.com, intel-gfx@lists.freedesktop.org,
	llvm@lists.linux.dev, ndesaulniers@google.com,
	patches@lists.linux.dev, dri-devel@lists.freedesktop.org,
	Nathan Chancellor <nathan@kernel.org>,
	Naresh Kamboju <naresh.kamboju@linaro.org>
Subject: [PATCH] drm/i915: Fix clang -Wimplicit-fallthrough in intel_async_flip_check_hw()
Date: Wed, 24 May 2023 08:38:27 -0700	[thread overview]
Message-ID: <20230524-intel_async_flip_check_hw-implicit-fallthrough-v1-1-83de89e376a1@kernel.org> (raw)

Clang warns:

  drivers/gpu/drm/i915/display/intel_display.c:6012:3: error: unannotated fall-through between switch labels [-Werror,-Wimplicit-fallthrough]
                  case I915_FORMAT_MOD_X_TILED:
                  ^
  drivers/gpu/drm/i915/display/intel_display.c:6012:3: note: insert 'break;' to avoid fall-through
                  case I915_FORMAT_MOD_X_TILED:
                  ^
                  break;
  1 error generated.

Clang is a little more pedantic than GCC, which does not warn when
falling through to a case that is just break or return. Clang's version
is more in line with the kernel's own stance in deprecated.rst, which
states that all switch/case blocks must end in either break,
fallthrough, continue, goto, or return. Add the missing break to silence
the warning.

Fixes: 937859485aef ("drm/i915: Support Async Flip on Linear buffers")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/202305241902.UvHtMoxa-lkp@intel.com/
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Closes: https://lore.kernel.org/CA+G9fYv68V3ewK0Qj-syQj7qX-hQr0H1MFL=QFNuDoE_J2Zu-g@mail.gmail.com/
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/gpu/drm/i915/display/intel_display.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 0490c6412ab5..6d49e0ab3e85 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -6008,6 +6008,7 @@ static int intel_async_flip_check_hw(struct intel_atomic_state *state, struct in
 					    plane->base.base.id, plane->base.name);
 				return -EINVAL;
 			}
+			break;
 
 		case I915_FORMAT_MOD_X_TILED:
 		case I915_FORMAT_MOD_Y_TILED:

---
base-commit: 9a2cb1b31c040e2f1b313e2f7921f0f5e6b66d82
change-id: 20230524-intel_async_flip_check_hw-implicit-fallthrough-c4c40b03802f

Best regards,
-- 
Nathan Chancellor <nathan@kernel.org>

