[PATCH -next v2] hwmon: (smpro-hwmon) Improve switch statments in smpro_is_visible()

From: Nathan Chancellor <nathan@kernel.org>
To: Jean Delvare <jdelvare@suse.com>, Guenter Roeck <linux@roeck-us.net>
Cc: Nick Desaulniers <ndesaulniers@google.com>,
	Tom Rix <trix@redhat.com>,
	Quan Nguyen <quan@os.amperecomputing.com>,
	linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org,
	llvm@lists.linux.dev, patches@lists.linux.dev,
	Nathan Chancellor <nathan@kernel.org>
Subject: [PATCH -next v2] hwmon: (smpro-hwmon) Improve switch statments in smpro_is_visible()
Date: Thu, 27 Oct 2022 16:16:12 -0700	[thread overview]
Message-ID: <20221027231611.3824800-1-nathan@kernel.org> (raw)

Clang warns:

  drivers/hwmon/smpro-hwmon.c:378:2: error: unannotated fall-through between switch labels [-Werror,-Wimplicit-fallthrough]
          default:
          ^
  drivers/hwmon/smpro-hwmon.c:378:2: note: insert 'break;' to avoid fall-through
          default:
          ^
          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. Additionally, adjust the
indentation of a break and add a default case to the inner switch
statement.

Fixes: a87456864cbb ("hwmon: Add Ampere's Altra smpro-hwmon driver")
Link: https://github.com/ClangBuiltLinux/linux/issues/1751
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---

v2:

    * Add missing default case to inner switch statement (Guenter)
    * Fix indentation of break in inner switch statement (Guenter)
    * Reword commit message to include these changes

v1: https://lore.kernel.org/20221027195238.1789586-1-nathan@kernel.org/

 drivers/hwmon/smpro-hwmon.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/smpro-hwmon.c b/drivers/hwmon/smpro-hwmon.c
index ee54e21c2c12..a76c49dd8438 100644
--- a/drivers/hwmon/smpro-hwmon.c
+++ b/drivers/hwmon/smpro-hwmon.c
@@ -373,8 +373,11 @@ static umode_t smpro_is_visible(const void *data, enum hwmon_sensor_types type,
 			ret = regmap_read(hwmon->regmap, temperature[channel].reg, &value);
 			if (ret || value == 0xFFFF)
 				return 0;
-		break;
+			break;
+		default:
+			break;
 		}
+		break;
 	default:
 		break;
 	}

base-commit: 0ffb687b6508c36a17b99bdaf014b38532404182
-- 
2.38.1

