On Sat, Jan 30, 2016 at 06:05:42PM -0800, Jarkko Sakkinen wrote: > The release-callback is not used before the device is attached to the > device hierarchy. This caused resources not to cleanup properly if the > device driver initialization failed before tpm_chip_register(). This commentary is not right, the release callback is callable immediately after device_initialize returns, it will be called by the last put_device(). > - * tpmm_chip_alloc() - allocate a new struct tpm_chip instance > - * @dev: device to which the chip is associated > + * tpmm_chip_alloc() - allocate and initialize a TPM chip > + * @pdev: the platform device who is the parent of the chip ? A platform device is not required, just something in a state that can handle devm. > + /* Associate character device with the platform device only after > + * it is properly initialized. > + */ > + dev_set_drvdata(pdev, chip); > + devm_add_action(pdev, (void (*)(void *)) tpm_dev_release, > &chip->dev); No, a release function can never be called naked. The action needs to do put_device, which is the error unwind for device_initialize(). > @@ -162,7 +165,10 @@ static int tpm_add_char_device(struct tpm_chip *chip) > MINOR(chip->dev.devt), rc); > > cdev_del(&chip->cdev); > - return rc; > + } else { > + devm_remove_action(chip->dev.parent, > + (void (*)(void *)) tpm_dev_release, > + &chip->dev); This is in the wrong place, the devm should be canceled only if tpm_chip_register returns success, at that point the caller's contract is to guarentee a call to tpm_chip_unregister, and tpm_chip_unregister does the put_device that calls the release function. Jason -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html