On Mon, 2022-05-02 at 12:11 +0200, Paolo Abeni wrote:

On Sat, 2022-04-30 at 13:56 +0000, Juhee Kang wrote:

quoted

Replace open code related to bit operation with BIT macros, which kernel
provided. This patch provides no functional change.

[]

quoted

diff --git a/drivers/net/amt.c b/drivers/net/amt.c

[]

quoted

@@ -959,7 +959,7 @@ static void amt_req_work(struct work_struct *work)
 	amt_update_gw_status(amt, AMT_STATUS_SENT_REQUEST, true);
 	spin_lock_bh(&amt->lock);
 out:
-	exp = min_t(u32, (1 * (1 << amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
+	exp = min_t(u32, (1 * BIT(amt->req_cnt)), AMT_MAX_REQ_TIMEOUT);
 	mod_delayed_work(amt_wq, &amt->req_wq, msecs_to_jiffies(exp * 1000));
 	spin_unlock_bh(&amt->lock);
 }

diff --git a/include/net/amt.h b/include/net/amt.h

[]

quoted

@@ -354,7 +354,7 @@ struct amt_dev {
 #define AMT_MAX_GROUP		32
 #define AMT_MAX_SOURCE		128
 #define AMT_HSIZE_SHIFT		8
-#define AMT_HSIZE		(1 << AMT_HSIZE_SHIFT)
+#define AMT_HSIZE		BIT(AMT_HSIZE_SHIFT)
 
 #define AMT_DISCOVERY_TIMEOUT	5000
 #define AMT_INIT_REQ_TIMEOUT	1

Even if the 2 replaced statements use shift operations, they do not
look like bit manipulation: the first one is an exponential timeout,
the 2nd one is an (hash) size. I think using the BIT() macro here will
be confusing.

I agree.

I also believe one of the uses of amt->req_cnt is error prone.

	drivers/net/amt.c:946:  if (amt->req_cnt++ > AMT_MAX_REQ_COUNT) {

Combining a test and post increment is not a great style IMO.
Is this really the intended behavior?