[PATCH] Input: evdev: avoid storing newest SYN_REPORT when dropping all events
From: Aniroop Mathur <hidden>
Date: 2015-12-24 19:24:19
Also in:
lkml
Subsystem:
input (keyboard, mouse, joystick, touchscreen) drivers, the rest · Maintainers:
Dmitry Torokhov, Linus Torvalds
The newest event can be SYN_REPORT in case of dropping all old events when buffer is full, but as now there is no device data available to read so lets drop SYN_REPORT as well and store only SYN_DROPPED. Signed-off-by: Aniroop Mathur <redacted> --- drivers/input/evdev.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index e9ae3d5..e270219 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c@@ -228,7 +228,7 @@ static int evdev_set_clk_type(struct evdev_client *client, unsigned int clkid) return 0; } -static void __pass_event(struct evdev_client *client, +static int __pass_event(struct evdev_client *client, const struct input_event *event) { client->buffer[client->head++] = *event;
@@ -247,12 +247,24 @@ static void __pass_event(struct evdev_client *client, client->buffer[client->tail].value = 0; client->packet_head = client->tail; + + /* + * Do not store SYN_REPORT as there is no device data in buffer + * and return to avoid wakeup and changing packet_head. + */ + if (event->type == EV_SYN && event->code == SYN_REPORT) { + client->head--; + client->head &= client->bufsize - 1; + return 1; + } } if (event->type == EV_SYN && event->code == SYN_REPORT) { client->packet_head = client->head; kill_fasync(&client->fasync, SIGIO, POLL_IN); } + + return 0; } static void evdev_pass_values(struct evdev_client *client,
@@ -287,7 +299,8 @@ static void evdev_pass_values(struct evdev_client *client, event.type = v->type; event.code = v->code; event.value = v->value; - __pass_event(client, &event); + if (__pass_event(client, &event)) + wakeup = false; } spin_unlock(&client->buffer_lock);
--
2.6.2