Re: pca953x: Probing too early

[Fabio Estevam <festevam@xxxxxxxxx>]

On Tue, Aug 20, 2024 at 5:45 PM Frank Li <Frank.li@xxxxxxx> wrote:

> what cause probe failure? I think it should be defer probe if some resource
> are not ready yet.

The failure happens because i2c-2 is probed after the pca953x driver:

[    1.898258] pca953x 2-0020: probe with driver pca953x failed with error -11
[    1.905575] i2c i2c-2: IMX I2C adapter registered

PCA953x tries to write to a register, but the I2C bus is not ready yet.

At which point in the driver I should check for the I2C controller
presence and return -EPROBE_DEFER if it is not ready?

Thanks