platform/x86: panasonic-laptop: Return errno correctly in show callback

[ Upstream commit 5c7bebc1a3f0661db558d60e14dde27fc216d9dc ]

When an error occurs in sysfs show callback, we should return the errno
directly instead of formatting it as the result, which produces
meaningless output and doesn't inform the userspace of the error.

Fixes: 468f96bfa3a0 ("platform/x86: panasonic-laptop: Add support for battery charging threshold (eco mode)")
Fixes: d5a81d8e864b ("platform/x86: panasonic-laptop: Add support for optical driver power in Y and W series")
Signed-off-by: Yao Zi <ziyao@disroot.org>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20241118064637.61832-3-ziyao@disroot.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/platform/x86/panasonic-laptop.c b/drivers/platform/x86/panasonic-laptop.c
index 26f4d15c3bf1383a81be305781d195532d27e0af..e412a550f09831f5218265addc12f8e1cba02426 100644 (file)
--- a/drivers/platform/x86/panasonic-laptop.c
+++ b/drivers/platform/x86/panasonic-laptop.c
@@ -602,8 +602,7 @@ static ssize_t eco_mode_show(struct device *dev, struct device_attribute *attr,
                result = 1;
                break;
        default:
-               result = -EIO;
-               break;
+               return -EIO;
        }
        return sysfs_emit(buf, "%u\n", result);
 }
@@ -749,7 +748,12 @@ static ssize_t current_brightness_store(struct device *dev, struct device_attrib
 static ssize_t cdpower_show(struct device *dev, struct device_attribute *attr,
                            char *buf)
 {
-       return sysfs_emit(buf, "%d\n", get_optd_power_state());
+       int state = get_optd_power_state();
+
+       if (state < 0)
+               return state;
+
+       return sysfs_emit(buf, "%d\n", state);
 }
 
 static ssize_t cdpower_store(struct device *dev, struct device_attribute *attr,