Re: [PATCH] Input: Add CLOCK_BOOTTIME Support

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Thu, Dec 18, 2014 at 05:12:29AM +0530, Aniroop Mathur wrote:
> Hello Mr. Torokhov,
> 
> On Thu, Dec 18, 2014 at 4:47 AM, Dmitry Torokhov
> <dmitry.torokhov@gmail.com> wrote:
> > On Thu, Dec 18, 2014 at 04:37:54AM +0530, Aniroop Mathur wrote:
> >> This patch adds support for CLOCK_BOOTTIME for input event timestamp.
> >> CLOCK_BOOTTIME includes suspend time, so it would allow aplications
> >> to get correct time difference between two events even when system
> >> resumes from suspend state.
> >>
> >> Signed-off-by: Aniroop Mathur <a.mathur@samsung.com>
> >> ---
> >>  drivers/input/evdev.c | 52 +++++++++++++++++++++++++++++++++++++--------------
> >>  1 file changed, 38 insertions(+), 14 deletions(-)
> >>
> >> diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
> >> index de05545..bfca214 100644
> >> --- a/drivers/input/evdev.c
> >> +++ b/drivers/input/evdev.c
> >> @@ -28,6 +28,13 @@
> >>  #include <linux/cdev.h>
> >>  #include "input-compat.h"
> >>
> >> +enum evdev_clock_type {
> >> +     EV_CLK_REAL = 0,
> >> +     EV_CLK_MONO,
> >> +     EV_CLK_BOOT,
> >> +     EV_CLK_MAX
> >> +};
> >> +
> >>  struct evdev {
> >>       int open;
> >>       struct input_handle handle;
> >> @@ -49,12 +56,29 @@ struct evdev_client {
> >>       struct fasync_struct *fasync;
> >>       struct evdev *evdev;
> >>       struct list_head node;
> >> -     int clkid;
> >> +     int clk_type;
> >>       bool revoked;
> >>       unsigned int bufsize;
> >>       struct input_event buffer[];
> >>  };
> >>
> >> +static int evdev_set_clk_type(int id, struct evdev_client *client)
> >> +{
> >> +     switch (id) {
> >> +
> >> +     case CLOCK_REALTIME:
> >> +             client->clk_type = EV_CLK_REAL; break;
> >> +     case CLOCK_MONOTONIC:
> >> +             client->clk_type = EV_CLK_MONO; break;
> >> +     case CLOCK_BOOTTIME:
> >> +             client->clk_type = EV_CLK_BOOT; break;
> >
> > Please put "break" on separate lines.
> >
> >> +     default:
> >> +             return -EINVAL;
> >> +     }
> >> +
> >> +     return 0;
> >> +}
> >> +
> >>  /* flush queued events of type @type, caller must hold client->buffer_lock */
> >>  static void __evdev_flush_queue(struct evdev_client *client, unsigned int type)
> >>  {
> >> @@ -108,8 +132,9 @@ static void evdev_queue_syn_dropped(struct evdev_client *client)
> >>       struct input_event ev;
> >>       ktime_t time;
> >>
> >> -     time = (client->clkid == CLOCK_MONOTONIC) ?
> >> -             ktime_get() : ktime_get_real();
> >> +     time = (client->clk_type == EV_CLK_REAL) ?
> >> +             ktime_get_real() : (client->clk_type == EV_CLK_MONO) ?
> >> +             ktime_get() : ktime_get_boottime();
> >>
> >>       ev.time = ktime_to_timeval(time);
> >>       ev.type = EV_SYN;
> >> @@ -159,7 +184,7 @@ static void __pass_event(struct evdev_client *client,
> >>
> >>  static void evdev_pass_values(struct evdev_client *client,
> >>                       const struct input_value *vals, unsigned int count,
> >> -                     ktime_t mono, ktime_t real)
> >> +                     ktime_t *ev_time)
> >>  {
> >>       struct evdev *evdev = client->evdev;
> >>       const struct input_value *v;
> >> @@ -169,8 +194,7 @@ static void evdev_pass_values(struct evdev_client *client,
> >>       if (client->revoked)
> >>               return;
> >>
> >> -     event.time = ktime_to_timeval(client->clkid == CLOCK_MONOTONIC ?
> >> -                                   mono : real);
> >> +     event.time = ktime_to_timeval(ev_time[client->clk_type]);
> >>
> >>       /* Interrupts are disabled, just acquire the lock. */
> >>       spin_lock(&client->buffer_lock);
> >> @@ -198,21 +222,22 @@ static void evdev_events(struct input_handle *handle,
> >>  {
> >>       struct evdev *evdev = handle->private;
> >>       struct evdev_client *client;
> >> -     ktime_t time_mono, time_real;
> >> +     ktime_t ev_time[EV_CLK_MAX];
> >>
> >> -     time_mono = ktime_get();
> >> -     time_real = ktime_mono_to_real(time_mono);
> >> +     ev_time[EV_CLK_MONO] = ktime_get();
> >> +     ev_time[EV_CLK_REAL] = ktime_mono_to_real(ev_time[EV_CLK_MONO]);
> >> +     ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_BOOT],
> >> +                                              TK_OFFS_BOOT);
> >
> > Nope, that should have read
> >
> >         ev_time[EV_CLK_BOOT] = ktime_mono_to_any(ev_time[EV_CLK_BOOT],
> >                                                  TK_OFFS_BOOT);
> >
> 
> Ahhh... okay need to change BOOT to MONO

Ugh, apparently I failed to actually type properly what I meant. Glad
you still understood me ;)

Thanks.

-- 
Dmitry