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    Subject[34-longterm 185/260] i2c-pca: Fix waitforcompletion() return value
    Date
    From: Yegor Yefremov <yegor_sub1@visionsystems.de>

    commit 6abb930af064fb1cf4177d32e2c7bfb89eee0fe5 upstream.

    ret is still -1, if during the polling read_byte() returns at once
    with I2C_PCA_CON_SI set. So ret > 0 would lead *_waitforcompletion()
    to return 0, in spite of the proper behavior.

    The routine was rewritten, so that ret has always a proper value,
    before returning.

    Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
    Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
    Signed-off-by: Jean Delvare <khali@linux-fr.org>
    Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
    ---
    drivers/i2c/busses/i2c-pca-isa.c | 12 ++++++++----
    drivers/i2c/busses/i2c-pca-platform.c | 11 +++++++----
    2 files changed, 15 insertions(+), 8 deletions(-)

    diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
    index f7346a9..62a5ce5 100644
    --- a/drivers/i2c/busses/i2c-pca-isa.c
    +++ b/drivers/i2c/busses/i2c-pca-isa.c
    @@ -71,8 +71,8 @@ static int pca_isa_readbyte(void *pd, int reg)

    static int pca_isa_waitforcompletion(void *pd)
    {
    - long ret = ~0;
    unsigned long timeout;
    + long ret;

    if (irq > -1) {
    ret = wait_event_timeout(pca_wait,
    @@ -81,11 +81,15 @@ static int pca_isa_waitforcompletion(void *pd)
    } else {
    /* Do polling */
    timeout = jiffies + pca_isa_ops.timeout;
    - while (((pca_isa_readbyte(pd, I2C_PCA_CON)
    - & I2C_PCA_CON_SI) == 0)
    - && (ret = time_before(jiffies, timeout)))
    + do {
    + ret = time_before(jiffies, timeout);
    + if (pca_isa_readbyte(pd, I2C_PCA_CON)
    + & I2C_PCA_CON_SI)
    + break;
    udelay(100);
    + } while (ret);
    }
    +
    return ret > 0;
    }

    diff --git a/drivers/i2c/busses/i2c-pca-platform.c b/drivers/i2c/busses/i2c-pca-platform.c
    index 5b2213d..1d8c208 100644
    --- a/drivers/i2c/busses/i2c-pca-platform.c
    +++ b/drivers/i2c/busses/i2c-pca-platform.c
    @@ -80,8 +80,8 @@ static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)
    static int i2c_pca_pf_waitforcompletion(void *pd)
    {
    struct i2c_pca_pf_data *i2c = pd;
    - long ret = ~0;
    unsigned long timeout;
    + long ret;

    if (i2c->irq) {
    ret = wait_event_timeout(i2c->wait,
    @@ -90,10 +90,13 @@ static int i2c_pca_pf_waitforcompletion(void *pd)
    } else {
    /* Do polling */
    timeout = jiffies + i2c->adap.timeout;
    - while (((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
    - & I2C_PCA_CON_SI) == 0)
    - && (ret = time_before(jiffies, timeout)))
    + do {
    + ret = time_before(jiffies, timeout);
    + if (i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
    + & I2C_PCA_CON_SI)
    + break;
    udelay(100);
    + } while (ret);
    }

    return ret > 0;
    --
    1.7.3.3


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