We normally avoid sending ZLPs by padding NTBs with a zero byte if the NTB is shorter than dwNtbOutMaxSize, resulting in a short USB packet instead of a ZLP. But in the case where the NTB length is exactly dwNtbOutMaxSize and this is an exact multiplum of wMaxPacketSize, then we must send a ZLP. This fixes an issue seen on a Sierra Wireless MC7710 device where the transmission would fail whenever we ended up padding the NTBs to max size. Signed-off-by: Bjørn Mork <bjorn@xxxxxxx> --- drivers/net/usb/cdc_mbim.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c index 42f51c7..3a5673a 100644 --- a/drivers/net/usb/cdc_mbim.c +++ b/drivers/net/usb/cdc_mbim.c @@ -366,7 +366,7 @@ err: static const struct driver_info cdc_mbim_info = { .description = "CDC MBIM", - .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN, + .flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN | FLAG_SEND_ZLP, .bind = cdc_mbim_bind, .unbind = cdc_mbim_unbind, .manage_power = cdc_mbim_manage_power, -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html