If last event in old queue that was dropped was EV_SYN/SYN_REPORT, then
lets generate EV_SYN/SYN_REPORT immediately after queing EV_SYN/SYN_DROPPED
so that clients would not ignore next valid full packet events.
Signed-off-by: Aniroop Mathur <a.mathur@xxxxxxxxxxx>
---
drivers/input/evdev.c | 45 +++++++++++++++++++++++++++++++++------------
1 file changed, 33 insertions(+), 12 deletions(-)
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index e9ae3d5..0bc7b98 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -156,7 +156,12 @@ static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
static void __evdev_queue_syn_dropped(struct evdev_client *client)
{
struct input_event ev;
+ struct input_event *prev_ev;
ktime_t time;
+ unsigned int mask = client->bufsize - 1;
+
+ /* store previous event */
+ prev_ev = &client->buffer[(client->head - 1) & mask];
time = client->clk_type == EV_CLK_REAL ?
ktime_get_real() :
@@ -170,13 +175,28 @@ static void __evdev_queue_syn_dropped(struct evdev_client *client)
ev.value = 0;
client->buffer[client->head++] = ev;
- client->head &= client->bufsize - 1;
+ client->head &= mask;
if (unlikely(client->head == client->tail)) {
/* drop queue but keep our SYN_DROPPED event */
- client->tail = (client->head - 1) & (client->bufsize - 1);
+ client->tail = (client->head - 1) & mask;
client->packet_head = client->tail;
}
+
+ /*
+ * If last packet was completely stored, then queue SYN_REPORT
+ * so that clients would not ignore next valid full packet
+ */
+ if (prev_ev->type == EV_SYN && prev_ev->code == SYN_REPORT) {
+ prev_ev->time = ev.time;
+ client->buffer[client->head++] = *prev_ev;
+ client->head &= mask;
+ client->packet_head = client->head;
+
+ /* drop queue but keep our SYN_DROPPED & SYN_REPORT event */
+ if (unlikely(client->head == client->tail))
+ client->tail = (client->head - 2) & mask;
+ }
}
static void evdev_queue_syn_dropped(struct evdev_client *client)
@@ -235,18 +255,19 @@ static void __pass_event(struct evdev_client *client,
client->head &= client->bufsize - 1;
if (unlikely(client->head == client->tail)) {
+ client->packet_head = client->tail;
+ __evdev_queue_syn_dropped(client);
+
/*
- * This effectively "drops" all unconsumed events, leaving
- * EV_SYN/SYN_DROPPED plus the newest event in the queue.
+ * Store newest event in the queue,
+ * but if it is SYN_REPORT then it is already stored by
+ * __evdev_queue_syn_dropped, so should not be stored again.
+ * As buffer overrun just occurred so no need to check here.
*/
- client->tail = (client->head - 2) & (client->bufsize - 1);
-
- client->buffer[client->tail].time = event->time;
- client->buffer[client->tail].type = EV_SYN;
- client->buffer[client->tail].code = SYN_DROPPED;
- client->buffer[client->tail].value = 0;
-
- client->packet_head = client->tail;
+ if (event->type != EV_SYN && event->code != SYN_REPORT) {
+ client->buffer[client->head++] = *event;
+ client->head &= client->bufsize - 1;
+ }
}
if (event->type == EV_SYN && event->code == SYN_REPORT) {
--
1.7.9.5
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