The sequence number is constrained to a range of [0, 4095], which
is a total of 4096 values. The bitmask operation using `& 0xfff` is
used to perform this wrap-around. While this is functionally correct,
it obscures the intended semantic of a 4096-based wrap.
Using a modulo operation `% 4096u` makes the wrap-around logic
explicit and easier to understand. It clearly signals that the
sequence number cycles through a range of 4096 values.
It also makes the code robust against potential changes of the 4096
upper limit, especially when it becomes a non power of 2 value while
the AND(&) works solely for power of 2 values.
The use of `% 4096u` also guarantees that the modulo operation is
performed with unsigned arithmetic, preventing potential issues with
the signed types.
Suggested-by: Andy Shevchenko <andy@kernel.org>
Suggested-by: David Laight <david.laight.linux@gmail.com>
Signed-off-by: Abraham Samuel Adekunle <abrahamadekunle50@gmail.com>
---
drivers/staging/rtl8723bs/core/rtw_xmit.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/staging/rtl8723bs/core/rtw_xmit.c b/drivers/staging/rtl8723bs/core/rtw_xmit.c
index c41de6fd897b..5cfb6d1e9dae 100644
--- a/drivers/staging/rtl8723bs/core/rtw_xmit.c
+++ b/drivers/staging/rtl8723bs/core/rtw_xmit.c
@@ -943,7 +943,7 @@ s32 rtw_make_wlanhdr(struct adapter *padapter, u8 *hdr, struct pkt_attrib *pattr
if (psta) {
psta->sta_xmitpriv.txseq_tid[pattrib->priority]++;
- psta->sta_xmitpriv.txseq_tid[pattrib->priority] &= 0xFFF;
+ psta->sta_xmitpriv.txseq_tid[pattrib->priority] %= 4096u;
pattrib->seqnum = psta->sta_xmitpriv.txseq_tid[pattrib->priority];
SetSeqNum(hdr, pattrib->seqnum);
@@ -963,11 +963,11 @@ s32 rtw_make_wlanhdr(struct adapter *padapter, u8 *hdr, struct pkt_attrib *pattr
if (SN_LESS(pattrib->seqnum, tx_seq)) {
pattrib->ampdu_en = false;/* AGG BK */
} else if (SN_EQUAL(pattrib->seqnum, tx_seq)) {
- psta->BA_starting_seqctrl[pattrib->priority & 0x0f] = (tx_seq + 1) & 0xfff;
+ psta->BA_starting_seqctrl[pattrib->priority & 0x0f] = (tx_seq + 1) % 4096u;
pattrib->ampdu_en = true;/* AGG EN */
} else {
- psta->BA_starting_seqctrl[pattrib->priority & 0x0f] = (pattrib->seqnum + 1) & 0xfff;
+ psta->BA_starting_seqctrl[pattrib->priority & 0x0f] = (pattrib->seqnum + 1) % 4096u;
pattrib->ampdu_en = true;/* AGG EN */
}
}
--
2.34.1