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Date: Fri,  2 Feb 2024 01:22:47 -0800
In-Reply-To: <20240202092250.786276-1-saravanak@google.com>
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Subject: [PATCH v1 1/3] driver core: Fix device_link_flag_is_sync_state_only()
From: Saravana Kannan <saravanak@google.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, "Rafael J. Wysocki" <rafael@kernel.org>, 
	Saravana Kannan <saravanak@google.com>
Cc: Xu Yang <xu.yang_2@nxp.com>, kernel-team@android.com, 
	linux-kernel@vger.kernel.org
Content-Type: text/plain; charset="UTF-8"

device_link_flag_is_sync_state_only() correctly returns true on the flags
of an existing device link that only implements sync_state() functionality.
However, it incorrectly and confusingly returns false if it's called with
DL_FLAG_SYNC_STATE_ONLY.

This bug doesn't manifest in any of the existing calls to this function,
but fix this confusing behavior to avoid future bugs.

Fixes: 67cad5c67019 ("driver core: fw_devlink: Add DL_FLAG_CYCLE support to device links")
Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 drivers/base/core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 14d46af40f9a..52215c4c7209 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -284,10 +284,12 @@ static bool device_is_ancestor(struct device *dev, struct device *target)
 	return false;
 }
 
+#define DL_MARKER_FLAGS		(DL_FLAG_INFERRED | \
+				 DL_FLAG_CYCLE | \
+				 DL_FLAG_MANAGED)
 static inline bool device_link_flag_is_sync_state_only(u32 flags)
 {
-	return (flags & ~(DL_FLAG_INFERRED | DL_FLAG_CYCLE)) ==
-		(DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED);
+	return (flags & ~DL_MARKER_FLAGS) == DL_FLAG_SYNC_STATE_ONLY;
 }
 
 /**
-- 
2.43.0.594.gd9cf4e227d-goog