From 63a6404d8ae693e71ab27c4f9c4032aa29113e92 Mon Sep 17 00:00:00 2001 From: Henrik Rydberg Date: Thu, 10 Jun 2010 12:05:24 -0700 Subject: Input: evdev - use driver hint to compute size of event buffer Some devices, in particular MT devices, produce a lot of data. This may lead to overflowing of the event queues in evdev driver, which by default are fairly small. Let the drivers hint the average number of events per packet generated by the device, and use that information when computing the buffer size evdev should use for the device. Signed-off-by: Henrik Rydberg Acked-by: Chase Douglas Signed-off-by: Dmitry Torokhov --- drivers/input/evdev.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index cff7bf9351a..30836c05edd 100644 --- a/drivers/input/evdev.c +++ b/drivers/input/evdev.c @@ -10,7 +10,8 @@ #define EVDEV_MINOR_BASE 64 #define EVDEV_MINORS 32 -#define EVDEV_MIN_BUFFER_SIZE 64 +#define EVDEV_MIN_BUFFER_SIZE 64U +#define EVDEV_BUF_PACKETS 8 #include #include @@ -245,7 +246,11 @@ static int evdev_release(struct inode *inode, struct file *file) static unsigned int evdev_compute_buffer_size(struct input_dev *dev) { - return EVDEV_MIN_BUFFER_SIZE; + unsigned int n_events = + max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS, + EVDEV_MIN_BUFFER_SIZE); + + return roundup_pow_of_two(n_events); } static int evdev_open(struct inode *inode, struct file *file) -- cgit v1.2.3-70-g09d2