CCID could send zero-length packet (ZLP)
if we invoke two data_in, two packets would be concated
and we could not distinguish them.
The CANOKEY_EMU_EP_CTAPHID is imported from canokey-qemu.h
Reported-by: MkfsSion <myychina28...@gmail.com>
Signed-off-by: Hongren (Zenithal) Zheng <i...@zenithal.me>
---
hw/usb/canokey.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/hw/usb/canokey.c b/hw/usb/canokey.c
index 4a08b1cbd7..86548923eb 100644
--- a/hw/usb/canokey.c
+++ b/hw/usb/canokey.c
@@ -109,11 +109,10 @@ int canokey_emu_transmit(
* Note: this is a quirk for CanoKey CTAPHID
* because it calls multiple emu_transmit in one device_loop
* but w/o data_in it would stuck in device_loop
- * This has no side effect for CCID as it is strictly
- * OUT then IN transfer
- * However it has side effect for Control transfer
+ * This has side effect for CCID since CCID can send ZLP
+ * This also has side effect for Control transfer
*/
- if (ep_in != 0) {
+ if (ep_in == CANOKEY_EMU_EP_CTAPHID) {
canokey_emu_data_in(ep_in);
}
return 0;
--
2.35.1
