| Message ID | 20240715151824.90033-2-eichest@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | i2c: imx: prevent rescheduling in non-dma mode | expand |
On Mon, Jul 15, 2024 at 05:17:51PM +0200, Stefan Eichenberger wrote: > From: Stefan Eichenberger <stefan.eichenberger@toradex.com> > > According to the reference manual it is only necessary to poll for bus I supposed it should be "According to i2c spec", > busy and arbitration lost in multi master mode. This helps to avoid > rescheduling while the i2c bus is busy and avoids SMBus devices to > timeout. > Reviewed-by: Frank Li <Frank.Li@nxp.com> > Signed-off-by: Stefan Eichenberger <stefan.eichenberger@toradex.com> > --- > drivers/i2c/busses/i2c-imx.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index 3842e527116b7..1add946e3bc20 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 +1473,8 @@ static int i2c_imx_probe(struct platform_device *pdev) > goto rpm_disable; > } > > + i2c_imx->multi_master = of_property_read_bool(pdev->dev.of_node, "multi-master"); > + > /* Set up clock divider */ > i2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ; > ret = of_property_read_u32(pdev->dev.of_node, > -- > 2.43.0 >
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 3842e527116b7..1add946e3bc20 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 +1473,8 @@ static int i2c_imx_probe(struct platform_device *pdev) goto rpm_disable; } + i2c_imx->multi_master = of_property_read_bool(pdev->dev.of_node, "multi-master"); + /* Set up clock divider */ i2c_imx->bitrate = I2C_MAX_STANDARD_MODE_FREQ; ret = of_property_read_u32(pdev->dev.of_node,