From 385b40b4fc1b54ade551c4fa56ece51364ab323e Mon Sep 17 00:00:00 2001 From: Alexander Sverdlin Date: Fri, 13 Jul 2018 17:20:17 +0200 Subject: [PATCH] i2c: davinci: Avoid zero value of CLKH [ 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(-) diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index b8c4353..5cf670f 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -234,12 +234,16 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev) /* * 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); } -- 2.7.4