From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=74.125.82.178 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792499280; b=EqtAw+8QwxsjF94GuksDGFAnYHzZZE7WEv0XWRirutLaCuq346LbvsBs6AG2FKqPCRDJ qjrdbRLs9+m1kp7AokA48f7urtYrOmprd57JgB+Ap10TCBddokV9hceapl3NvhsqD5sgf DHkenpk/pKE+FHVrFMKtwxCEqIBaMcH7vM5fQ1LNfK6HL4t1j/BSb9zq7PUGhGbHcUPSM gfMdKRhmIrVSMYt3NQO3SHN27wfLQBUDxVNUD13A4rIrU3fX5+odJIPnuTUh7P0H9k7Qz Hnc7xz04ds9Qs0v5Efux+paj3HK+nleQ4SqXiI0BlvnJtOtFja+YgvK4ohFxlXoroig== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792499280; h=DMARC-Filter:Received:DKIM-Signature:X-Google-DKIM-Signature: X-Forwarded-Encrypted:X-Gm-Message-State:X-Gm-Gg:X-Received:Received: From:To:Cc:Subject:Date:Message-ID:X-Mailer:In-Reply-To:References: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=P0QwVqIkHLHAsRie0NBb7Fm4JU4R0zkfzukQ7suLbX0=; b=gkWuYusUKzrNEVDehkfoOyb3XU9J+bMqXbXnxWKKU7vszbhG0mveDz6yrOVHBZKRLeFq KAeCPaae4E69YMRcj7cqHINcYccRNCFc+cMfZvbewZdUkfxPzvYFrMmOWf2CoBEdudmE+ LpeUAVygUzz7KNT/N1qSALUAEK+5Y0P4KZswlNGmhGP4gDzlxQzMrIGKZ43c5335hTI8+ fZugkap9CoXPSlemeurikidpcPJhVRLZk5/eODzkL++SQYMnmAxGyq8sKM3bqhzTaLe8l gygTYzve2ZuPwoLOrODbeTZJh2aghK/+segOp8Axknbf4vc4x9E0svZPDbDvab0M+PQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=q1nMmDHq; arc=none smtp.remote-ip=74.125.82.178 Received: from mail-dy1-f178.google.com (mail-dy1-f178.google.com [74.125.82.178]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 916CA606A320 for ; Tue, 20 Oct 2026 12:28:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 916CA606A320 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, unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=q1nMmDHq Received: by mail-dy1-f178.google.com with SMTP id 5a478bee46e88-36661f953e4so770349eec.1 for ; Tue, 20 Oct 2026 05:28:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1792499280; x=1793104080; darn=vger.kernel.org; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:from:to:cc:subject :date:message-id:reply-to:content-type; bh=P0QwVqIkHLHAsRie0NBb7Fm4JU4R0zkfzukQ7suLbX0=; b=q1nMmDHq2C4UkjrZNeo6tN+Zd5a+7kHiLMyrQd5OUTLT06LjSe4LRyhah/BIvNBrJI +5nGjTsb1wjU3Q111fpXxDGi0f9Dj9h6Q7hyvudp7ryrlSdatr+UI91fVmiyh0iKRNte G4f0cIWPCy2eldzVRkBuNayjxQpkRdhuLa3JDCtao9VHgu+FOcKv21VAkW1ud+VzMmFq 3z+WCiiOTLq1rLrenEjOA0mHoXqXIBN1sL+hSk6tXejz/HTxuTwnK21K6hJLW5vOQtyu vCABdffmvZkOtGiGr7xZYOE2ccHGoE45y2+mIU6Tm6xVpVkJ65hajHFMbiGIYzoACpN0 O2Pw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792499280; x=1793104080; h=content-transfer-encoding:content-type:mime-version:references :in-reply-to:message-id:date:subject:cc:to:from:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=P0QwVqIkHLHAsRie0NBb7Fm4JU4R0zkfzukQ7suLbX0=; b=FdCKv+iczbfM/vAhIEi4IAqRaAtqJVXg6ALHLMTfd5mJLNMm5TON44JzQR1f64qFOh t2Xs5i+0aOBRyhbLvLUN+lHL9zjFP88LdpO/ebK3yjqS7ZganPQGzACF46ATagc9Rns1 wyUqZFXWkNb1CPOqC3tIRLyrxD9SwPckgCmVW78ZRIjf7pL58YNcXBgm05A1QahjHbS3 WKLg/AoIHnUHh7OBUoYxZ3l3FQgMTBDyBDciBe+rumNVzNIQgTGpZT+geHNp0XG0nWjj rn3Bq16AVHjEGcaMLJ8DgRauzoCbXYmZtwqNQWu1ZvVZYhaWmivgufySNXWqgyDJmd0P +vGA== X-Forwarded-Encrypted: i=1; AKwUvBwWxfFsp1sOoBykS1F52azgtEvC7LIppfbJev0YFQ4slm6IAxSRgAbgg6qlAvgRLUGrl7n6wT1G0GHv7Y4=@vger.kernel.org X-Gm-Message-State: AFq9FYL4WURxh69ih5Zite1YtRahDVh3BtTrC42zkjfVQZXLou5OBP5h WmWCtbwcjKwMBYdkIi0gOSTjkxlP8iYIyQ0LAN/kZ5upVH1KDPff3Cgw X-Gm-Gg: AYBFou235EdTj4devqrV2xif0rQ5+fFlTMS8vA8/AaaACwta4JA6ReYVPICIOK01+DM A/fk/SW+HKnUiuj3apYMVBVuI2PDc3BCUvJy1KFMTWoniuuqac0RKwe1JQ3b5HO9ul3vOKv4IYh 1zG4JkFb4Rk2vFPfoqo2no6LD5+ajhcBWWwTG7NxGYnGNVqvgvY0bcSaAhfWKuL+9ebclPz8Pik HyygpZMhMiDY3bk6BEuCPl+2Vd7Mru1FqKY093xOdXXkcon/N4IRRThWf/jwEs0mRMDmv2M32he qKKXdmhhtLcMP+DJ8PwPwNfOab2V71j5dUet4EQyWVkGdjHcQxmvMW32f01S4a+g9nk2Jcwt//N ekBuT9uGNRtIm1+Zx3w+2f90exnH9YuoEALHs+MU7mD8fgQ3Mw0lwoQoBMcgLv6Z+l9rzaouKUP JoMP3L8/B8DytQGr0SY6+6XDu8mmD2k4IFH7nROOxVuzr6uZ8BVGS85m14vbbH2yFdXtk5eovTL zpHUJv1DhNhyFJOTIY1jbC/SwxdEhzaKtKR00fbjAkajFP91vzCBrBWOUlzbY8v9pSiAHxpndDf oypONQ== X-Received: by 2002:a05:701b:4302:b0:165:1f2c:5c1b with SMTP id a92af1059eb24-1850d37060emr13962847c88.4.1792499279662; Tue, 20 Oct 2026 05:27:59 -0700 (PDT) Received: from MaquinaLab.. ([179.179.238.247]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-1831b75ac0fsm36015493c88.15.2026.10.20.05.27.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 20 Oct 2026 05:27:59 -0700 (PDT) From: Vinicius Pedrosa To: ilpo.jarvinen@linux.intel.com Cc: andriy.shevchenko@linux.intel.com, jirislaby@kernel.org, linux-serial@vger.kernel.org, gregkh@linuxfoundation.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-sunxi@lists.linux.dev, andre.przywara@arm.com, wens@kernel.org, jernej.skrabec@gmail.com, samuel@sholland.org, enzo.adriano.code@gmail.com Subject: Re: [PATCH v2 2/4] serial: 8250_dw: Only accept a contiguous DLF readback Date: Tue, 20 Oct 2026 09:27:46 -0300 Message-ID: <20261020122746.41699-1-vinicius.eduardo.pedrosa@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <09812a6a-dd0d-9c47-e1ad-5220f1954648@linux.intel.com> References: <09812a6a-dd0d-9c47-e1ad-5220f1954648@linux.intel.com> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Ilpo, On Tue, 20 Oct 2026, Ilpo Järvinen wrote: > For is_power_of_2(), 0 is not a power of two. And it also wouldn't make > sense to have zero bits in the bit field as it's same as no bit field so > using just is_power_of_2() should be enough. I think the reg != 0 check still needs to stay here, since the test is is_power_of_2(reg + 1), rather than is_power_of_2(reg). For reg == 0, reg + 1 is 1, and is_power_of_2(1) is true. So without the explicit reg check, a zero readback, meaning no DLF, would be accepted as a valid DLF. I'll keep it as: reg && is_power_of_2(reg + 1) in v3. Thanks, Vinicius