scdaemon (possible?) lockup

NIIBE Yutaka gniibe at
Wed Oct 5 09:32:02 CEST 2016

On 10/05/2016 04:07 PM, Fabio Coatti wrote:
> Given that, a try would be to look a the code of scd to check the behaviour 
> when an error occurs and if the error state can be exited in some way, and 
> look at timeouts/retries to read the card.


> 1. for some reason, when scd enters the "card error status" he can't
> get off until reloaded.

Perhaps related somehow, scdaemon had a bug about card removal
handling.  It was fixed in:

    Author:     NIIBE Yutaka <gniibe at>
    AuthorDate: Sat Sep 3 15:27:30 2016 +0900

It will be included in the next release (2.1.16).

I don't know how the power management of the card reader works.  If
it's in USB layer (it causes USB error), I think that scdaemon can
detect an error correctly.  If it's card communication layer, it is
likely something wrong may happen with scdaemon in version 2.1.15, and
the scdaemon continues until reload.

Are there any specification or explanation about the power management of
the reader?

More information about the Gnupg-devel mailing list