> 在 2015年11月3日，09:43，Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> 写道： > > On Mon, Nov 02, 2015 at 09:35:36PM +0800, WEN Pingbo wrote: >> Before this, I have discussed this problem with Arnd. And Arnd have >> an idea that by converting timeval to long / long in input_event, so that >> input_event structure size will be unchanged, and timeval structure will >> removed entirely. But we also need to avoid using CLOCK_REALTIME in >> userland, to keep the new input_event structure y2038 safe. >> >> The input_event will only support monotonic time in Arnd's idea. And >> we still need to add wall time support for old 32-bit binary. >> >> Those patches try to keep original input capacity, and resolve y2038 >> problem in input_event radically. >> >> struct input_event is only used between kernel and userspace >> communication (except uinput). So that we can replace input_event >> with input_event64 in kernel entirely, and add a conversion in >> input_event_from/to_user() to keep compatible with old 32-bits binary. >> >> userland can switch to input_event64, which is y2038 safe, via ioctl. > > If we are forcing userspace to change the protocol I'd rather explore > whether we need to transmit the timestamp in each and every event. I > would much rather drop it and instead introduce new event code for > timestamp (we already have MSC_TIMESTAMP for hardware-generated > timestamps, maybe we can introduce new ones for kernel-generated > timestamps). Yes, we can do that by replacing all input_event with input_value in kernel, and injecting a timestamp event after every normal event (maybe we can give userspace a option here). But we still need do some conversion work in input_event_from/to_user to be compatible with old binary. And we need extend value field in ’struct input_value’ to s64, so the timestamp can be passed safely. Pingbo-- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
