From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8BA5525BEFF for ; Thu, 19 Jun 2025 13:23:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750339421; cv=none; b=sVKxKZMEQ7JfZaOI0f510qpKnc01Tb6PKFC8GC/rOsiLysvw54ENkDYaPdkqkpNNweQkPWeV3SHZbZ9etABoZC+NrFhPH9akLfVFvESfl5UrWbjlhDoQMM/aUCQx9qATVmk/YijoCgLbfVkGA2SLVarNZNmBTtYmZzCR1zCU7A4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750339421; c=relaxed/simple; bh=yvTf0gRwf8lcvYmPdwBfIAWvG4ZTR+XJziAnsjuaLbY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Wz3kM1auEgBK3i9CmihimL+Z1p6KC+qfQi3wEQIzYVTax/1VN3Pc3qJpuwD7/YffkjO06kSKZHQVno8c4WHSIlgj1Y8qBpadqs/LRh1fiPEuRw4Uw2+qnnVd08QZvBBvnqnv2pYXaRgsRmUW4pSE5sDQe2jWsO0Kxl2z/+gGL0M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=jBsgkAYi; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="jBsgkAYi" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1750339418; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=oRlc/455JdnZehorRTgWTdsui2EMVuSES1pT6cJjXLE=; b=jBsgkAYifvsCqB3C7zKWiji+ij1MID3eBbTcGlpJTCzs21s4w2f3Zr8WINY2Qc8R7F9667 hbFd26dfo1yWyU/fiygbLyjFVjPuMTnyIH2GhsNeiA3BW5XyUZjRXdV5wSweaJq5KqHFzm D8BTf0QT+JLcjqJylFqJdqWfV4OmyRQ= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-495-rXXmzHykOaeYBn076ZPozg-1; Thu, 19 Jun 2025 09:23:37 -0400 X-MC-Unique: rXXmzHykOaeYBn076ZPozg-1 X-Mimecast-MFC-AGG-ID: rXXmzHykOaeYBn076ZPozg_1750339416 Received: by mail-wm1-f70.google.com with SMTP id 5b1f17b1804b1-451d2037f1eso4811915e9.0 for ; Thu, 19 Jun 2025 06:23:37 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750339416; x=1750944216; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=oRlc/455JdnZehorRTgWTdsui2EMVuSES1pT6cJjXLE=; b=KruUB3Ve5EACb+KpDq0uXyzjsO5FnrA8KK7rUpJQUZ5eAMMFKwtYB23YuaJ42AijkN F5SVAlVi9R+DU59Z7o9EmzEwR9aEaBraQsiIPd2BJf1LQbO/pfJg0d59frVbs39AzwHm ehQ/ntEsRhHRok0y3ltUg3J8HYudnaK7BTqGaOb97QCdt0fx5DIY1LyZzxH2AArrujGr o5Rad/p/mzz1EH1ifesmTMNKE0JTrmLqOsMTg+33kXBac24iaPZSuVI5l1NnH8ZTq1yR s321Y6We4n7lznY4lmXXXXEucQLM50DRh/IHknziFGF9R0e+GXvd7Ag9686KIQPwNIuM wdrg== X-Forwarded-Encrypted: i=1; AJvYcCWzvS+m6GQNeZTxloFZFvk64Vky2tI/JtVIWBXRuehA+0Vj0G90vKxPVOz89P9+xidDtuOdGl/b0To=@vger.kernel.org X-Gm-Message-State: AOJu0YyUhqy/dTFg9SKQ09CMBjBoQCyJ5bTG69cb6yF7xiTdOCIP2+Rw shsV/V2HHpluOKvjmvGCMk+0T/40rXeN6BMUD/flH0JSopHU0zKq7jH0+BG6nPt2Ii0lw/vbFYd c1uTHG8HgUF3zMO8DovBkTdxDBfVw0JZJh1ZFZkgyH1XuDQFAToSRpiQvY6YZOQ== X-Gm-Gg: ASbGncvxjQ/SYxGWS3kDlUAUJrsDQm5w4LObD5xnPUix/HWsoT1fD20DPh9bHBBE2Af iDfdFTI6vFpt7oDA0vMh5SRSDzg3/AGiTsw/kzhHdwzBV6EaoT8o2CGVD97lxKpOyKwOyPb+3Fx /vJ9zr/2GHemsCrfeTo7oT8jtEXSxOWY8yr8NbQDCqBj8W3fYhbgK4C+tXSQFQoUq9s0WLXxDJX nECWW8FF/BaV2hUdedlmI7IXx3ty2F67Xc4hhLOfHskvvtXemfA4cHLId5sU05pVLKL8yNBAIyR f2aei404P2V2weO0ZG/XC8/42av6pg== X-Received: by 2002:a05:600c:4f43:b0:448:e8c0:c778 with SMTP id 5b1f17b1804b1-453514a1e54mr102985225e9.22.1750339416155; Thu, 19 Jun 2025 06:23:36 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFzq+77XzI783Jt8YUI6h/miSxke49tHCSnFqIWVHg/I3AY/81H+u1Iauzwvv3Q5jdGX1Wv2g== X-Received: by 2002:a05:600c:4f43:b0:448:e8c0:c778 with SMTP id 5b1f17b1804b1-453514a1e54mr102984925e9.22.1750339415703; Thu, 19 Jun 2025 06:23:35 -0700 (PDT) Received: from ?IPV6:2a0d:3344:271a:7310::f39? ([2a0d:3344:271a:7310::f39]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-45362219d3dsm8413635e9.26.2025.06.19.06.23.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 19 Jun 2025 06:23:33 -0700 (PDT) Message-ID: <45b79d7d-dc26-491b-b5e6-c5f5ab210850@redhat.com> Date: Thu, 19 Jun 2025 15:23:31 +0200 Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net-next v11 13/14] dpll: zl3073x: Add support to get/set frequency on input pins To: Vadim Fedorenko , Ivan Vecera , netdev@vger.kernel.org Cc: Prathosh Satish , Arkadiusz Kubalewski , Jiri Pirko , Rob Herring , Krzysztof Kozlowski , Conor Dooley , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Simon Horman , Jonathan Corbet , Jason Gunthorpe , Shannon Nelson , Dave Jiang , Jonathan Cameron , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, Michal Schmidt , Petr Oros References: <20250616201404.1412341-1-ivecera@redhat.com> <20250616201404.1412341-14-ivecera@redhat.com> <72bab3b2-bdd6-43f6-9243-55009f9c1071@redhat.com> Content-Language: en-US From: Paolo Abeni In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 6/19/25 2:15 PM, Vadim Fedorenko wrote: > On 19/06/2025 12:15, Paolo Abeni wrote: >> On 6/16/25 10:14 PM, Ivan Vecera wrote: >>> +/** >>> + * zl3073x_dpll_input_ref_frequency_get - get input reference frequency >>> + * @zldpll: pointer to zl3073x_dpll >>> + * @ref_id: reference id >>> + * @frequency: pointer to variable to store frequency >>> + * >>> + * Reads frequency of given input reference. >>> + * >>> + * Return: 0 on success, <0 on error >>> + */ >>> +static int >>> +zl3073x_dpll_input_ref_frequency_get(struct zl3073x_dpll *zldpll, u8 ref_id, >>> + u32 *frequency) >>> +{ >>> + struct zl3073x_dev *zldev = zldpll->dev; >>> + u16 base, mult, num, denom; >>> + int rc; >>> + >>> + guard(mutex)(&zldev->multiop_lock); >>> + >>> + /* Read reference configuration */ >>> + rc = zl3073x_mb_op(zldev, ZL_REG_REF_MB_SEM, ZL_REF_MB_SEM_RD, >>> + ZL_REG_REF_MB_MASK, BIT(ref_id)); >>> + if (rc) >>> + return rc; >>> + >>> + /* Read registers to compute resulting frequency */ >>> + rc = zl3073x_read_u16(zldev, ZL_REG_REF_FREQ_BASE, &base); >>> + if (rc) >>> + return rc; >>> + rc = zl3073x_read_u16(zldev, ZL_REG_REF_FREQ_MULT, &mult); >>> + if (rc) >>> + return rc; >>> + rc = zl3073x_read_u16(zldev, ZL_REG_REF_RATIO_M, &num); >>> + if (rc) >>> + return rc; >>> + rc = zl3073x_read_u16(zldev, ZL_REG_REF_RATIO_N, &denom); >>> + if (rc) >>> + return rc; >>> + >>> + /* Sanity check that HW has not returned zero denominator */ >>> + if (!denom) { >>> + dev_err(zldev->dev, >>> + "Zero divisor for ref %u frequency got from device\n", >>> + ref_id); >>> + return -EINVAL; >>> + } >>> + >>> + /* Compute the frequency */ >>> + *frequency = base * mult * num / denom; >> >> As base, mult, num and denom are u16, the above looks like integer >> overflow prone. >> >> I think you should explicitly cast to u64, and possibly use a u64 frequency. > > I might be a good idea to use mul_u64_u32_div together with mul_u32_u32? > These macroses will take care of overflow on 32bit platforms as well. I guess such macros will work, but u64 is available on 32bits platform as well - and possibly simpler/more readable. /P