diff options
Diffstat (limited to 'scd/ccid-driver.c')
| -rw-r--r-- | scd/ccid-driver.c | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/scd/ccid-driver.c b/scd/ccid-driver.c index 7124c6e7a..1a01ff0a1 100644 --- a/scd/ccid-driver.c +++ b/scd/ccid-driver.c @@ -2073,17 +2073,28 @@ ccid_open_reader (const char *spec_reader_name, int idx, int ccid_require_get_status (ccid_driver_t handle) { + /* When a card reader supports interrupt transfer to check the + status of card, it is possible to submit only an interrupt + transfer, and no check is required by application layer. USB can + detect removal of a card and can detect removal of a reader. + */ if (handle->ep_intr >= 0) return 0; - /* Here comes products check for tokens which - always have card inserted. */ - switch (handle->id_vendor) - { - case VENDOR_FSIJ: - return 0; - } + /* Libusb actually detects the removal of USB device in use. + However, there is no good API to handle the removal (yet), + cleanly and with good portability. + + There is libusb_set_pollfd_notifiers function, but it doesn't + offer libusb_device_handle* data to its callback. So, when it + watches multiple devices, there is no way to know which device is + removed. + Once, we will have a good programming interface of libusb, we can + list tokens (with no interrupt transfer support, but always with + card inserted) here to return 0, so that scdaemon can submit + minimum packet on wire. + */ return 1; } |