From patchwork Fri Feb 2 06:55:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Slaby X-Patchwork-Id: 769443 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 AEFD317755; Fri, 2 Feb 2024 06:56:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706856973; cv=none; b=lXvyu0cAw/xxDKKwHzf07VmWxNQWTg3qq4gUUNWou13Iw/d9CZVqpJMSVOei2lAC3jHrAONXoZvlXfP0lPuwOiVqCpohYu7zZfiJk6gKtSAwx9fpqdjMis0P8xCgmOK00gTkavIkVU/gMXIsIvghaj1OG6jkGcSO+6mb7F49nFk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706856973; c=relaxed/simple; bh=zh855z9zkcp82mqscxhofAUAlll2wwDk2/8ndqNudGY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MTKWp91PtU062uDAQloOj43r8LFdxUjzFzi3MzmL6gQcWZ0KqkVq2irigxTshr+K23BMM90DPpBbv90oTHzQ5lH4thbQjGKHcsbg3Rkfa/qgGNuyTeaY7Yd+jX9VGBbYDVRrBE7wVyy35p+OXifXAP9yqrcDnw/RaBYp6RbCUAM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JFgEKrM5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="JFgEKrM5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7240BC433C7; Fri, 2 Feb 2024 06:56:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1706856973; bh=zh855z9zkcp82mqscxhofAUAlll2wwDk2/8ndqNudGY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JFgEKrM5wTITV5azZ2L6F8afa5eFIYHYdLzpw31YAcYR868VOQ4TDnFbC4fhj2Jmx RfQZ1Hvihyw6XGtCweIMchTGuv+VATe4pmExZ/TxBAUMC70k61HOAVSYYXY9+hpuX2 3nw+vzq4CDMssgtsWrwNqwnUj8TQouzM+NtS8yJJsMdOPG1FwKtJJsgybizSX35u2F 4F5RPgzaYT4+JKrrCZWxUNgkNUTfRTvrYISst3cJ3VLNoJ6nY/iAH+vTf4EA8Etgqg AV3Zpcw/Z9ux2H0JpmqvmSO4/oSCv0HQtpNkVZQEcfuG+eE9SwbTQmPnPqtrMHrXy9 qetFvHcDPPMeg== From: "Jiri Slaby (SUSE)" To: gregkh@linuxfoundation.org Cc: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org, "Jiri Slaby (SUSE)" Subject: [PATCH 01/22] tty: vt: make rgb_from_256() slighly more comprehensible Date: Fri, 2 Feb 2024 07:55:47 +0100 Message-ID: <20240202065608.14019-2-jirislaby@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240202065608.14019-1-jirislaby@kernel.org> References: <20240202065608.14019-1-jirislaby@kernel.org> Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 * make the parameter unsigned, as it is expected to be unsigned, * make the computation easier to follow -- step-by-step, and * don't use 85 / 2 which is only a reduced form of 255 / 6 (by a factor 3). Unlike the former, the latter can be understood. Signed-off-by: Jiri Slaby (SUSE) --- drivers/tty/vt/vt.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 65cd40cac96b..7d42f148559a 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -1588,7 +1588,7 @@ static void default_attr(struct vc_data *vc) struct rgb { u8 r; u8 g; u8 b; }; -static void rgb_from_256(int i, struct rgb *c) +static void rgb_from_256(unsigned int i, struct rgb *c) { if (i < 8) { /* Standard colours. */ c->r = i&1 ? 0xaa : 0x00; @@ -1599,9 +1599,12 @@ static void rgb_from_256(int i, struct rgb *c) c->g = i&2 ? 0xff : 0x55; c->b = i&4 ? 0xff : 0x55; } else if (i < 232) { /* 6x6x6 colour cube. */ - c->r = (i - 16) / 36 * 85 / 2; - c->g = (i - 16) / 6 % 6 * 85 / 2; - c->b = (i - 16) % 6 * 85 / 2; + i -= 16; + c->b = i % 6 * 255 / 6; + i /= 6; + c->g = i % 6 * 255 / 6; + i /= 6; + c->r = i * 255 / 6; } else /* Grayscale ramp. */ c->r = c->g = c->b = i * 10 - 2312; }