From: Ryo Kataoka <[email protected]> Even if R-Car I2C received NACK, after that it might receive ACK by HW auto restart. In case of that, driver would continue process. If R-Car I2C didn't receive ACK, the driver would detect timeout and would report NACK as -ENXIO.
Signed-off-by: Ryo Kataoka <[email protected]> Signed-off-by: Yoshihiro Kaneko <[email protected]> --- This patch is based on i2c/for-next branch of Wolfram Sang's linux tree. drivers/i2c/busses/i2c-rcar.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c index 71a6e07..dde8abf 100644 --- a/drivers/i2c/busses/i2c-rcar.c +++ b/drivers/i2c/busses/i2c-rcar.c @@ -455,14 +455,20 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr) if (msr & MNR) { /* go to stop phase */ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP); - rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP); rcar_i2c_flags_set(priv, ID_NACK); goto out; } /* Stop */ if (msr & MST) { - rcar_i2c_flags_set(priv, ID_DONE); + if (rcar_i2c_flags_has(priv, ID_NACK)) { + /* don't set ID_DONE for expecting ACK + after auto-restart by HW */ + rcar_i2c_write(priv, ICMSR, ~MST); + } else { + rcar_i2c_flags_set(priv, ID_DONE); + rcar_i2c_write(priv, ICMSR, 0); + } goto out; } @@ -536,15 +542,14 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap, rcar_i2c_flags_has(priv, ID_DONE), 5 * HZ); if (!timeout) { + if (rcar_i2c_flags_has(priv, ID_NACK)) { + ret = -ENXIO; + break; + } ret = -ETIMEDOUT; break; } - if (rcar_i2c_flags_has(priv, ID_NACK)) { - ret = -ENXIO; - break; - } - if (rcar_i2c_flags_has(priv, ID_ARBLOST)) { ret = -EAGAIN; break; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
