From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: Xing Zheng Cc: mturquette@baylibre.com, sboyd@codeaurora.org, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, dianders@chromium.org, briannorris@chromium.org, huangtao@rock-chips.com, zhangqing@rock-chips.com Subject: Re: [PATCH v3 7/7] clk: rockchip: rk3399: Add support frac mode frequencies Date: Thu, 04 Aug 2016 21:19:08 +0200 Message-ID: <12790025.3tRiQgk9GG@diego> In-Reply-To: <1470122579-32083-1-git-send-email-zhengxing@rock-chips.com> References: <1470122401-31934-1-git-send-email-zhengxing@rock-chips.com> <1470122579-32083-1-git-send-email-zhengxing@rock-chips.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" List-ID: Hi Xing, Am Dienstag, 2. August 2016, 15:22:59 schrieb Xing Zheng: > We need to support various display resolutions for external > display devices like HDMI/DP, the frac mode can help us to > acquire almost any frequencies, and need higher VCOs to reduce > clock jitters. > > Signed-off-by: Xing Zheng why does this need to be a separate rate array and cannot live in the general pll rate array? The plls are general purpose, so we shouldn't limit them arbitarily. I currently only see some frequencies (594MHz, 297MHz, 54MHz) that are present in both arrays but have different settings. As your patch description says that these settings reduce clock jitter, wouldn't the general frequencies also profit from merging these new values into the general rate array? Heiko