From nobody Tue Dec 16 16:38:49 2025 Received: from mail-ed1-f44.google.com (mail-ed1-f44.google.com [209.85.208.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 379CF204F77 for ; Mon, 7 Apr 2025 15:54:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.44 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744041249; cv=none; b=ndbVRtTXZM+boNMvr8guQ7rFfK62uZSpt/hQOEz0MfDGchRAFcpT1fedqTPz/LUN4xdm0Z5jZLtu3AQkwL1dyvFoxs+VWKAeGd9S4wgBa7NSvWA6Ko5toF5jfHqxG9IO/21oxje+Zp1PUKafTzZjajLmSd7Udf4AIUmueQ4/WWo= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744041249; c=relaxed/simple; bh=WDaDUGwmEwERewTKyabJp/z9rCF2mx3zI4Bzn0WShS8=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=f8mm6uRUFDjJu4BMHqUbrJf9M2Q9LmyWDg0pjvZ9Ol01Kr0pANkyvdl0+4NEuRBkHr3FjyA9PJghtJ61IAgPAHyNyDqji/0ECByAfIULy7TCxWskxAlm2PkaC2BAPx6bIWh8wnefklLnXFozaaHiA70U7uB6G3eq4HcRKbcc058= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=ADQf/COk; arc=none smtp.client-ip=209.85.208.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ADQf/COk" Received: by mail-ed1-f44.google.com with SMTP id 4fb4d7f45d1cf-5e5e22e6ed2so6613789a12.3 for ; Mon, 07 Apr 2025 08:54:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1744041245; x=1744646045; darn=vger.kernel.org; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=l7zpBmQSttWP+7fm7BnZXVdnmr4f6nnR4NTtCIBva+0=; b=ADQf/COk/cdjNbDchmwkEKdlNGijKKyrFDINo8l+ukk/LTvQe9v82EEMCMh5XZGc4O zenSXu55Bj5HUro4mHyou+qb4E3G0EBDvV5rY0L6rBNKOxFhrNw3PmqegyEE0AV01j5P PN7EB9hf455OnarznAmU26qRcgukF6IVyttEDXrIKXFDl8C6jhTjPh/ihPoDWQgmK1qR L9/zScxGeQJO4FFO6clsP3DY2HwYzaqV9NY5GEiL8JOsxxIBW4Fi4kjl+Twt6dCf8XVf 0JCMGIfmbmEClyRyiZYq5BpX7wyJeIp5sZWPfY/4KXDe8G1nxtmYdXudQ+5mnpTNDOGz PHQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744041245; x=1744646045; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=l7zpBmQSttWP+7fm7BnZXVdnmr4f6nnR4NTtCIBva+0=; b=iJ8qaFy4+79vaMAnboZCmNOSXQo+vTox1mSN8v/f8F1YHVEp3YoOQ2dD+Smg+pmsj0 hAvSR3uuEccv8G/ahDBBYYCYsEnIl/Ou0fZ6wrMgaW833OIKI22lZcbpcYMyKF1eckEi SFvQGbqdTaXbTDOQADyeKho1RIaev3Bfdwq6BPRPEGn1ZUneImAXEGpdeih3Y/IaYtrx T5JcnSHi8cR/k6fIn55g4x9wlbNDTeFGZCt3wbH7tNYN5i8Gl/2shZkiC7jOdVaZ/GJs 5XAs/QBSdXpMkBiw4vvJmJZ+DKegO+xuJ0vNRWUVQ7F8PtQovKSdNDLE2KOGXiUrYZ4T J/ig== X-Forwarded-Encrypted: i=1; AJvYcCVVXGohSVgrCJ+GmuC6LVgObNQF9yQVy3qGmptVX5x8VFq05dEbRF1esE++DFYDtSljRF7ZoOsOan+JTaE=@vger.kernel.org X-Gm-Message-State: AOJu0Ywf0w6bE09Do4piH0d6DgtQNyOGwSLMmL+pVtdY800vzl4mSlWy w2l9LNRONEkfd4ch16XXXEz+bGgdihPPLr3hiToulmHJY2NlGKdE X-Gm-Gg: ASbGncs7K7zBB5tsGqHYOPiWAenDdLN6HchqXPIpVtvPDa5zsTMU6AkLpHISbc518Va q5WYRqk+59lQDRJ+P7b3SM99zRs8qVzVJM1Jjr3tkfmjbUq8OLOX7oxGza5oRdLTtJc068cuAs7 kREGtn3eq3c4Oy6EJHYsMjcRz3Xj4dbUN7uZ/vtsKy1UqfeCkBeMTQzAx5bqq8GKIqTPLWvkW3T T2/LgS+kexW390g4J2JI/4frJwrIEXuHSFl4/kS098u4gNSA9cKfXT0vj2K70DnS8ZxAD0GrKvk 30qQduqcJpqbFV366yWnT6lGUWuL+4anQyDomZKtvSJn3/+KfwbCp6133EM= X-Google-Smtp-Source: AGHT+IGcEDBQMZ6NJ63PN9jaNGPysR18XtEQVLoJ9mJjYIPbmqYOBpKf30iNgs0lzXrb0qCoFmr1nw== X-Received: by 2002:a05:6402:3584:b0:5e0:9252:3550 with SMTP id 4fb4d7f45d1cf-5f0b5da540bmr11079775a12.2.1744041245290; Mon, 07 Apr 2025 08:54:05 -0700 (PDT) Received: from ubuntu ([105.112.123.61]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5f0d87e272csm4551681a12.47.2025.04.07.08.54.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Apr 2025 08:54:04 -0700 (PDT) Date: Mon, 7 Apr 2025 15:54:02 +0000 From: Abraham Samuel Adekunle To: gregkh@linuxfoundation.org, julia.lawall@inria.fr, outreachy@lists.linux.dev Cc: linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, david.laight.linux@gmail.com, andy@kernel.org, dan.carpenter@linaro.org Subject: [PATCH v5] staging: rtl8723bs: Use % 4096u instead of & 0xfff Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 Suggested-by: David Laight Signed-off-by: Abraham Samuel Adekunle --- Changes in v4: - Corrected patch to use '%' instead of '&' - To ensure this change does not affect the functional behaviour, I compared the generated object files before and after the change using the `cmp` which compares the two object files byte by byte as shown below: $ make drivers/staging/rtl8723bs/core/rtw_xmit.o $ cmp rtw_xmit_before.o rtw_xmit_after.o No differences were found in the output, confirming that the change does not alter the compiled output. Changes in v3: - Added more description to the commit message. - Removed blank line in the tag block. - Added more patch recipients. Changes in v2: - Changed the commit message t a more descriptive message which makes it clear why the patch does the change. - changed the subject title to include `4096u` to show that an unsigned module is used. Changes in v1: - Added more patch recipients. 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/rt= l8723bs/core/rtw_xmit.c index 026061b464f7..548fcf9968bd 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 =20 if (psta) { psta->sta_xmitpriv.txseq_tid[pattrib->priority]++; - psta->sta_xmitpriv.txseq_tid[pattrib->priority] &=3D 0xFFF; + psta->sta_xmitpriv.txseq_tid[pattrib->priority] %=3D 4096u; pattrib->seqnum =3D psta->sta_xmitpriv.txseq_tid[pattrib->priority]; =20 SetSeqNum(hdr, pattrib->seqnum); @@ -963,11 +963,11 @@ s32 rtw_make_wlanhdr(struct adapter *padapter, u8 *hd= r, struct pkt_attrib *pattr if (SN_LESS(pattrib->seqnum, tx_seq)) { pattrib->ampdu_en =3D false;/* AGG BK */ } else if (SN_EQUAL(pattrib->seqnum, tx_seq)) { - psta->BA_starting_seqctrl[pattrib->priority & 0x0f] =3D (tx_seq+1)&0= xfff; + psta->BA_starting_seqctrl[pattrib->priority & 0x0f] =3D (tx_seq+1)%4= 096u; =20 pattrib->ampdu_en =3D true;/* AGG EN */ } else { - psta->BA_starting_seqctrl[pattrib->priority & 0x0f] =3D (pattrib->se= qnum+1)&0xfff; + psta->BA_starting_seqctrl[pattrib->priority & 0x0f] =3D (pattrib->se= qnum+1)%4096u; pattrib->ampdu_en =3D true;/* AGG EN */ } } --=20 2.34.1