Re: [PATCH v3 02/20] Input: Improve the events-per-packet estimate

From: Dmitry Torokhov
Date: Thu Sep 13 2012 - 01:16:13 EST


On Sat, Sep 01, 2012 at 09:46:57PM +0200, Henrik Rydberg wrote:
> The events-per-packet estimate has so far been used by MT devices
> only. This patch adjusts the packet buffer size to also accomodate the
> KEY and MSC events. Keyboards normally send one or two keys at a
> time. MT devices normally send a number of button keys along with the
> MT information. The buffer size chosen here covers those cases, and
> matches the default buffer size in evdev. Since the input estimate is
> now preferred, remove the special input-mt estimate.
>
> Reviewed-by: Ping Cheng <pingc@xxxxxxxxx>
> Signed-off-by: Henrik Rydberg <rydberg@xxxxxxxxxxx>

Makes sense.

Acked-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>

> ---
> drivers/input/input-mt.c | 1 -
> drivers/input/input.c | 10 +++++++---
> 2 files changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
> index c6df704..58bde77 100644
> --- a/drivers/input/input-mt.c
> +++ b/drivers/input/input-mt.c
> @@ -42,7 +42,6 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots)
> mt->num_slots = num_slots;
> input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);
> input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0);
> - input_set_events_per_packet(dev, 6 * num_slots);
>
> /* Mark slots as 'unused' */
> for (i = 0; i < num_slots; i++)
> diff --git a/drivers/input/input.c b/drivers/input/input.c
> index 6e90705..8ebf116 100644
> --- a/drivers/input/input.c
> +++ b/drivers/input/input.c
> @@ -1777,6 +1777,9 @@ static unsigned int input_estimate_events_per_packet(struct input_dev *dev)
> if (test_bit(i, dev->relbit))
> events++;
>
> + /* Make room for KEY and MSC events */
> + events += 7;
> +
> return events;
> }
>
> @@ -1815,6 +1818,7 @@ int input_register_device(struct input_dev *dev)
> {
> static atomic_t input_no = ATOMIC_INIT(0);
> struct input_handler *handler;
> + unsigned int packet_size;
> const char *path;
> int error;
>
> @@ -1827,9 +1831,9 @@ int input_register_device(struct input_dev *dev)
> /* Make sure that bitmasks not mentioned in dev->evbit are clean. */
> input_cleanse_bitmasks(dev);
>
> - if (!dev->hint_events_per_packet)
> - dev->hint_events_per_packet =
> - input_estimate_events_per_packet(dev);
> + packet_size = input_estimate_events_per_packet(dev);
> + if (dev->hint_events_per_packet < packet_size)
> + dev->hint_events_per_packet = packet_size;
>
> /*
> * If delay and period are pre-set by the driver, then autorepeating
> --
> 1.7.12
>

--
Dmitry
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