Commit 2222e0a6 authored by Alexander Graf's avatar Alexander Graf Committed by Gerd Hoffmann
Browse files

input: Add trace event for empty keyboard queue 



When driving QEMU from the outside, we have basically no chance to
determine how quickly the guest OS picks up key events, so we usually
have to limit ourselves to very slow keyboard presses to make sure
the guest always has enough chance to pick them up.

This patch adds a trace events when the keyboarde queue is drained.
An external driver can use that as hint that new keys can be pressed.

Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
Message-id: 1490883775-94658-1-git-send-email-agraf@suse.de
Signed-off-by: default avatarGerd Hoffmann <kraxel@redhat.com>
parent 05c6638b

hw/input/hid.c

+4 −0
Original line number Diff line number Diff line
@@ -256,6 +256,10 @@ static void hid_keyboard_process_keycode(HIDState *hs) 
    slot = hs->head & QUEUE_MASK; QUEUE_INCR(hs->head); hs->n--;

    keycode = hs->kbd.keycodes[slot];



    if (!hs->n) {

        trace_hid_kbd_queue_empty();

    }



    key = keycode & 0x7f;

    index = key | ((hs->kbd.modifiers & (1 << 8)) >> 1);

    hid_code = hid_usage_keys[index];

hw/input/trace-events

+1 −0
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ milkymist_softusb_pulse_irq(void) "Pulse IRQ" 


# hw/input/hid.c

hid_kbd_queue_full(void) "queue full"

hid_kbd_queue_empty(void) "queue empty"



# hw/input/virtio

virtio_input_queue_full(void) "queue full"