From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.coquelin@st.com (Maxime Coquelin) Date: Mon, 23 Feb 2015 10:42:12 +0100 Subject: [PATCH 3/3] clk: divider: fix calculation of initial best divider when rounding to closest In-Reply-To: <1424515225-6929-4-git-send-email-u.kleine-koenig@pengutronix.de> References: <20150221085620.GV19388@pengutronix.de> <1424515225-6929-1-git-send-email-u.kleine-koenig@pengutronix.de> <1424515225-6929-4-git-send-email-u.kleine-koenig@pengutronix.de> Message-ID: <54EAF5F4.3070509@st.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Uwe, On 02/21/2015 11:40 AM, Uwe Kleine-K?nig wrote: > Similar to the reasoning for the previous commit > > DIV_ROUND_CLOSEST(parent_rate, rate) > > might not be the best integer divisor to get a good approximation for > rate from parent_rate (given the metric for CLK_DIVIDER_ROUND_CLOSEST). > > For example assume a parent rate of 1000 Hz and a target rate of 700. > Using DIV_ROUND_CLOSEST the suggested divisor gets calculated to 1 > resulting in a target rate of 1000 with a delta of 300 to the desired > rate. With choosing 2 as divisor however the resulting rate is 500 which > is nearer to 700. > > Signed-off-by: Uwe Kleine-K?nig > --- > drivers/clk/clk-divider.c | 13 +++++++------ > 1 file changed, 7 insertions(+), 6 deletions(-) > This is correct. Thanks for fixing this. You can add my: Acked-by: Maxime Coquelin Best regards, Maxime