sddm shows "Authentication failed", though user is logged in successfully afterwards

[Christoph]

Hello,

I created a PAM configuration that first tries to login a user with a smartcard and the appropriate PIN, and if that fails, then tries to login the user with the traditional UNIX password. This on the whole works as desired, but I saw that, if UNIX authentication is used, a message "Authentication failed" appears on the sddm greeter screen for a short time before the user session starts. So, I  am wondering how at all sddm gets knowledge about some failed PAM module. Should it not just receive the final pam_authenticate() result, which obviously is PAM_SUCCESS in this case, for otherwise the login would really fail? Are there any other means how sddm gets the result of the failed smartcard authentication?

Regards

  Christoph