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This helps to avoid rescheduling while the i2c bus is busy and avoids SMBus devices to timeout. For backward compatibility, the single-master property needs to be explicitly set to disable the bus busy polling. Signed-off-by: Stefan Eichenberger Reviewed-by: Frank Li Acked-by: Oleksij Rempel --- @Frank and Oleksij: I kept your tags even though I made multi-master the new default. Let me know if you have any objections. drivers/i2c/busses/i2c-imx.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 98539313cbc97..d697abd2459d4 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -216,6 +216,8 @@ struct imx_i2c_struct { struct i2c_client *slave; enum i2c_slave_event last_slave_event; + bool multi_master; + /* For checking slave events. */ spinlock_t slave_lock; struct hrtimer slave_timer; @@ -481,6 +483,9 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool a unsigned long orig_jiffies = jiffies; unsigned int temp; + if (!i2c_imx->multi_master) + return 0; + while (1) { temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR); @@ -540,8 +545,8 @@ static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic) return -ETIMEDOUT; } - /* check for arbitration lost */ - if (i2c_imx->i2csr & I2SR_IAL) { + /* In multi-master mode check for arbitration lost */ + if (i2c_imx->multi_master && (i2c_imx->i2csr & I2SR_IAL)) { dev_dbg(&i2c_imx->adapter.dev, "<%s> Arbitration lost\n", __func__); i2c_imx_clear_irq(i2c_imx, I2SR_IAL); @@ -1468,6 +1473,12 @@ static int i2c_imx_probe(struct platform_device *pdev) goto rpm_disable; } + /* + * We use the single-master property for backward compatibility. + * By default multi master mode is enabled. + */ + i2c_imx->multi_master = !of_property_read_bool(pdev->dev.of_node, "single-master"); + /* Set up clock divider */ i2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ; ret = of_property_read_u32(pdev->dev.of_node,