On Tue, Aug 20, 2024 at 8:18 PM Fabio Estevam <festevam@xxxxxxxxx> wrote: > The pca953x driver tries to write to the i2c-2 bus before i2c-2 is registered. > > This is the point I don't understand: how can the pca953x driver get > probed before its I2C bus parent? Disconsider what I wrote above. I'm trying to recover from the arbitration lost like this: --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -491,6 +491,8 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool a /* check for arbitration lost */ if (temp & I2SR_IAL) { i2c_imx_clear_irq(i2c_imx, I2SR_IAL); + pr_err("******* Arbitration lost\n"); + i2c_recover_bus(&i2c_imx->adapter); return -EAGAIN; } @@ -1487,6 +1489,7 @@ static int i2c_imx_probe(struct platform_device *pdev) i2c_imx->adapter.nr = pdev->id; i2c_imx->adapter.dev.of_node = pdev->dev.of_node; i2c_imx->base = base; + i2c_imx->adapter.retries = 5; ACPI_COMPANION_SET(&i2c_imx->adapter.dev, ACPI_COMPANION(&pdev->dev)); but still get pca953x probe failure: [ 1.756761] pca953x 2-0020: supply vcc not found, using dummy regulator [ 1.766564] pca953x 2-0020: using no AI [ 1.775333] ******* Arbitration lost [ 1.783811] ******* Arbitration lost [ 1.793701] ******* Arbitration lost [ 1.797455] ******* Arbitration lost [ 1.801209] ******* Arbitration lost [ 1.804964] ******* Arbitration lost [ 1.808562] pca953x 2-0020: failed writing register [ 1.813602] pca953x: probe of 2-0020 failed with error -11 [ 1.819222] i2c i2c-2: IMX I2C adapter registered