From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alexander Sverdlin , Sekhar Nori , Wolfram Sang , Sasha Levin Subject: [PATCH 4.14 041/165] i2c: davinci: Avoid zero value of CLKH Date: Mon, 3 Sep 2018 18:55:27 +0200 Message-Id: <20180903165657.184121399@linuxfoundation.org> In-Reply-To: <20180903165655.003605184@linuxfoundation.org> References: <20180903165655.003605184@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Sverdlin [ Upstream commit cc8de9a68599b261244ea453b38678229f06ada7 ] If CLKH is set to 0 I2C clock is not generated at all, so avoid this value and stretch the clock in this case. Signed-off-by: Alexander Sverdlin Acked-by: Sekhar Nori Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-davinci.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -234,12 +234,16 @@ static void i2c_davinci_calc_clk_divider /* * It's not always possible to have 1 to 2 ratio when d=7, so fall back * to minimal possible clkh in this case. + * + * Note: + * CLKH is not allowed to be 0, in this case I2C clock is not generated + * at all */ - if (clk >= clkl + d) { + if (clk > clkl + d) { clkh = clk - clkl - d; clkl -= d; } else { - clkh = 0; + clkh = 1; clkl = clk - (d << 1); }