From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roel Kluin Subject: [PATCH 2/2 v2] i2c,algo: handle timeout correctly Date: Fri, 06 Feb 2009 14:11:46 +0100 Message-ID: <498C3712.2000904@gmail.com> References: <4984688B.2090805@gmail.com> <20090201114121.6448a3c9@hyperion.delvare> <498760F7.6020005@gmail.com> <20090202225309.359e77d6@hyperion.delvare> <49883938.9010104@gmail.com> <20090204093402.08ddb2e8@hyperion.delvare> <4989BD34.9050406@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4989BD34.9050406-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jean Delvare Cc: ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ebrower-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org List-Id: linux-i2c@vger.kernel.org Let's first adress the other issues at hand. This patch should be applied on top of my previous cleanup patch --------------------------->8---------------------8<--------------------------- With a postfix decrement these timeouts reach -1 rather than 0, but after the loop it is tested whether they have become 0. As pointed out by Jean Delvare, the msg_num should be tested before the timeout. With the current order, you could exit with a timeout error while all the messages were successfully transferred. Signed-off-by: Roel Kluin --- diff --git a/drivers/i2c/algos/i2c-algo-pcf.c b/drivers/i2c/algos/i2c-algo-pcf.c index ce916d7..2862f11 100644 --- a/drivers/i2c/algos/i2c-algo-pcf.c +++ b/drivers/i2c/algos/i2c-algo-pcf.c @@ -115,15 +115,17 @@ static int wait_for_bb(struct i2c_algo_pcf_data *adap) status = get_pcf(adap, 1); - while (timeout-- && !(status & I2C_PCF_BB)) { + while (!(status & I2C_PCF_BB) && --timeout) { udelay(100); /* wait for 100 us */ status = get_pcf(adap, 1); } - if (timeout <= 0) + if (timeout == 0) { printk(KERN_ERR "Timeout waiting for Bus Busy\n"); + return -ETIMEDOUT; + } - return timeout <= 0; + return 0; } static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) @@ -133,7 +135,7 @@ static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) *status = get_pcf(adap, 1); - while (timeout-- && (*status & I2C_PCF_PIN)) { + while ((*status & I2C_PCF_PIN) && --timeout) { adap->waitforpin(adap->data); *status = get_pcf(adap, 1); } @@ -142,10 +144,10 @@ static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) return -EINTR; } - if (timeout <= 0) - return -1; - else - return 0; + if (timeout == 0) + return -ETIMEDOUT; + + return 0; } /*