From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: [PATCH 2/2] i2c: (algo-pca) Fix mode selection for PCA9665 Date: Wed, 12 Sep 2012 20:39:51 -0700 Message-ID: <1347507591-32352-2-git-send-email-linux@roeck-us.net> References: <1347507591-32352-1-git-send-email-linux@roeck-us.net> Return-path: In-Reply-To: <1347507591-32352-1-git-send-email-linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean Delvare , Ben Dooks Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Thomas Kavanagh , Wolfram Sang , Guenter Roeck List-Id: linux-i2c@vger.kernel.org From: Thomas Kavanagh As implemented, the code always selects turbo mode for PCA9665, no matter which clock frequency is configured. This is because it compares clock boundaries against constants reflecting (boundary / 100), but uses the actual clock frequency to compare against. To fix the problem, use a variable reflecting (clock / 100), not the actual clock frequency, when comparing against (boundary / 100). Cc: Wolfram Sang Signed-off-by: Thomas Kavanagh Signed-off-by: Guenter Roeck --- drivers/i2c/algos/i2c-algo-pca.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/i2c/algos/i2c-algo-pca.c b/drivers/i2c/algos/i2c-algo-pca.c index 07ccbef..572251b 100644 --- a/drivers/i2c/algos/i2c-algo-pca.c +++ b/drivers/i2c/algos/i2c-algo-pca.c @@ -477,17 +477,17 @@ static int pca_init(struct i2c_adapter *adap) /* To avoid integer overflow, use clock/100 for calculations */ clock = pca_clock(pca_data) / 100; - if (pca_data->i2c_clock > 10000) { + if (clock > 10000) { mode = I2C_PCA_MODE_TURBO; min_tlow = 14; min_thi = 5; raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */ - } else if (pca_data->i2c_clock > 4000) { + } else if (clock > 4000) { mode = I2C_PCA_MODE_FASTP; min_tlow = 17; min_thi = 9; raise_fall_time = 22; /* Raise 11e-8s, Fall 11e-8s */ - } else if (pca_data->i2c_clock > 1000) { + } else if (clock > 1000) { mode = I2C_PCA_MODE_FAST; min_tlow = 44; min_thi = 20; -- 1.7.9.7