From 4535d654919bbf13c05809e5eba9329f2d698ee2 Mon Sep 17 00:00:00 2001 From: Steven Noonan Date: Thu, 22 Apr 2021 14:35:59 -0700 Subject: [PATCH] HIDAPI_UpdateDiscovery: only treat "add" and "remove" events as relevant I have a buggy system which reports a udev "change" event for an empty USB-C port every 0.14 seconds, which causes annoying frame hitches because SDL decides that means it needs to do a libusb hid_enumerate, which is slow (~25ms!) because of the get_usb_string() calls in there. We only need to re-enumerate if we've seen a device added or removed, so let's filter out the change event first. Signed-off-by: Steven Noonan Signed-off-by: Sam Lantinga --- src/joystick/hidapi/SDL_hidapijoystick.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/src/joystick/hidapi/SDL_hidapijoystick.c b/src/joystick/hidapi/SDL_hidapijoystick.c index 12eb59f24..e3f99bc98 100644 --- a/src/joystick/hidapi/SDL_hidapijoystick.c +++ b/src/joystick/hidapi/SDL_hidapijoystick.c @@ -442,10 +442,13 @@ HIDAPI_UpdateDiscovery() break; } - SDL_HIDAPI_discovery.m_bHaveDevicesChanged = SDL_TRUE; - pUdevDevice = usyms->udev_monitor_receive_device(SDL_HIDAPI_discovery.m_pUdevMonitor); if (pUdevDevice) { + const char *action = NULL; + action = usyms->udev_device_get_action(pUdevDevice); + if (!action || SDL_strcmp(action, "add") == 0 || SDL_strcmp(action, "remove") == 0) { + SDL_HIDAPI_discovery.m_bHaveDevicesChanged = SDL_TRUE; + } usyms->udev_device_unref(pUdevDevice); } }