On Mon, Nov 24, 2014 at 03:53:36PM -0600, Derek Foreman wrote:
> Instead of using a hard coded mouse DPI value, we query it from udev.
> If it's not present or the property is obviously broken we fall back
> to default.
for the archives: the thing we're struggling with on high-DPI mice is that
our pointer acceleration becomes rather useless. the DPI setting is
something we can't get from the device though, so our goal is to build a
udev database of "all" devices and go from there. once that is in place, we
expect the MOUSE_DPI property to be set and use that to calibrate our
pointer acceleration.
> Signed-off-by: Derek Foreman <der...@osg.samsung.com>
> ---
> src/evdev.c | 18 ++++++++++++++++++
> src/libinput-util.c | 41 +++++++++++++++++++++++++++++++++++++++++
> src/libinput-util.h | 2 ++
> 3 files changed, 61 insertions(+)
>
> diff --git a/src/evdev.c b/src/evdev.c
> index 36c6859..a2547c7 100644
> --- a/src/evdev.c
> +++ b/src/evdev.c
> @@ -1218,8 +1218,11 @@ evdev_need_mtdev(struct evdev_device *device)
> static void
> evdev_tag_device(struct evdev_device *device)
> {
> + struct libinput *libinput = device->base.seat->libinput;
> + const char *mouse_dpi;
> struct udev *udev;
> struct udev_device *udev_device = NULL;
> + int dpi;
>
> udev = udev_new();
> if (!udev)
> @@ -1229,6 +1232,21 @@ evdev_tag_device(struct evdev_device *device)
> if (udev_device) {
> if (device->dispatch->interface->tag_device)
> device->dispatch->interface->tag_device(device,
> udev_device);
> + mouse_dpi = udev_device_get_property_value(udev_device,
> "MOUSE_DPI");
> + if (mouse_dpi) {
> + dpi = udev_parse_mouse_dpi_property(mouse_dpi);
> + if (dpi)
> + device->dpi = dpi;
> + else {
> + log_error(libinput, "Mouse DPI property for"
> + " '%s' is present but "
> + "invalid, using %d DPI "
> + "instead\n",
> + device->devname,
> + DEFAULT_MOUSE_DPI);
> + device->dpi = DEFAULT_MOUSE_DPI;
> + }
> + }
> udev_device_unref(udev_device);
> }
> udev_unref(udev);
> diff --git a/src/libinput-util.c b/src/libinput-util.c
> index 34d5549..5600424 100644
> --- a/src/libinput-util.c
> +++ b/src/libinput-util.c
> @@ -28,7 +28,9 @@
>
> #include "config.h"
>
> +#include <ctype.h>
> #include <stdarg.h>
> +#include <stdbool.h>
> #include <stdio.h>
> #include <stdlib.h>
>
> @@ -113,3 +115,42 @@ ratelimit_test(struct ratelimit *r)
>
> return RATELIMIT_EXCEEDED;
> }
> +
> +int
> +udev_parse_mouse_dpi_property(const char *prop)
I'd prefer this not be named udev_... if it's a general utility. just drop
udev_ would be enough.
> +{
> + bool is_default = false;
> + int rd, dpi;
this is nitpicking, but I think we can afford the extra character storage to
have 'nread' instead of the harder-to-interpret 'rd' :)
> +
> + /* When parsing the mouse DPI property, if we find an error we
> + * just return 0 since it's obviously invalid, the caller will
> + * treat that as an error and use a reasonable default instead.
> + * If the property contains multiple DPI settings but none flagged
> + * as default, we return the last because we're lazy and that's
> + * a silly way to set the property anyway.
> + */
it'd be nice to add a comment here on how the property _should_ look like.
otherwise, looks good, thanks. I'll get the udev hwdb patches to the list
asap, just a heads up: I'm going to wait until those are merged before we
merge this just in case there are any last-minute changes.
Cheers,
Peter
> + while (*prop != 0) {
> + if (*prop == ' ') {
> + prop++;
> + continue;
> + }
> + if (*prop == '*') {
> + prop++;
> + is_default = true;
> + if (!isdigit(prop[0]))
> + return 0;
> + }
> +
> + rd = 0;
> + sscanf(prop, "%d@%*d%n", &dpi, &rd);
> + if (!rd)
> + sscanf(prop, "%d%n", &dpi, &rd);
> + if (!rd || dpi == 0 || prop[rd] == '@')
> + return 0;
check for negative dpi/frequency here pls
otherwise, looks good, thanks.
Cheers,
Peter
> +
> + if (is_default)
> + break;
> + prop += rd;
> + }
> + return dpi;
> +}
> diff --git a/src/libinput-util.h b/src/libinput-util.h
> index 909c9db..62d7ac1 100644
> --- a/src/libinput-util.h
> +++ b/src/libinput-util.h
> @@ -296,4 +296,6 @@ struct ratelimit {
> void ratelimit_init(struct ratelimit *r, uint64_t ival_ms, unsigned int
> burst);
> enum ratelimit_state ratelimit_test(struct ratelimit *r);
>
> +int udev_parse_mouse_dpi_property(const char *prop);
> +
> #endif /* LIBINPUT_UTIL_H */
> --
> 2.1.3
>
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> wayland-devel mailing list
> wayland-devel@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/wayland-devel
>
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