From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1034184AbcJ0WZs (ORCPT ); Thu, 27 Oct 2016 18:25:48 -0400 Received: from mail-oi0-f68.google.com ([209.85.218.68]:32942 "EHLO mail-oi0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965226AbcJ0WZp (ORCPT ); Thu, 27 Oct 2016 18:25:45 -0400 MIME-Version: 1.0 In-Reply-To: <20161027022420.GC31660@dtor-ws> References: <1476761253-13450-1-git-send-email-deepa.kernel@gmail.com> <1476761253-13450-4-git-send-email-deepa.kernel@gmail.com> <20161027022420.GC31660@dtor-ws> From: Deepa Dinamani Date: Thu, 27 Oct 2016 15:25:43 -0700 Message-ID: Subject: Re: [PATCH v2 3/4] input: Deprecate real timestamps beyond year 2106 To: Dmitry Torokhov Cc: linux-input@vger.kernel.org, Linux Kernel Mailing List , Arnd Bergmann , y2038 Mailman List , Peter Hutterer , Benjamin Tissoires , Jiri Kosina , Hans de Goede Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> struct timeval is not y2038 safe. >> All usage of timeval in the kernel will be replaced by >> y2038 safe structures. >> >> struct input_event maintains time for each input event. >> Real time timestamps are not ideal for input as this >> time can go backwards as noted in the patch a80b83b7b8 >> by John Stultz. Hence, having the input_event.time fields >> only big enough for monotonic and boot times are >> sufficient. >> >> Leave the original input_event as is. This is to maintain >> backward compatibility with existing userspace interfaces >> that use input_event. >> Introduce a new replacement struct raw_input_event. >> This replaces timeval with struct input_timeval. This structure >> maintains time in __kernel_ulong_t or compat_ulong_t to allow >> for architectures to override types as in the case of x32. >> >> The change requires any userspace utilities reading or writing >> from event nodes to update their reading format to match >> raw_input_event. The changes to the popular libraries will be >> posted along with the kernel changes. >> The driver version is also updated to reflect the change in >> event format. > > If users are forced to update to adapt to the new event format, should > we consider more radical changes? For example, does it make sense to > send timestamp on every event? Maybe we should only send it once per > event packet (between EV_SYN/SYN_REPORT)? What granularity do we need? > Is there anything else in current protocol that we'd like to change? I did see the thread with Pingbo's patches where you had a similar comment. I see my series as decoupling the kernel input event format from the userspace format. The formats also are really the same still. Could this be considered the first step towards changing the protocol? The protocol changes might need new interfaces to be defined between libraries. And, could end up being a substantial change. Would a step by step approach make sense? -Deepa From mboxrd@z Thu Jan 1 00:00:00 1970 From: Deepa Dinamani Subject: Re: [PATCH v2 3/4] input: Deprecate real timestamps beyond year 2106 Date: Thu, 27 Oct 2016 15:25:43 -0700 Message-ID: References: <1476761253-13450-1-git-send-email-deepa.kernel@gmail.com> <1476761253-13450-4-git-send-email-deepa.kernel@gmail.com> <20161027022420.GC31660@dtor-ws> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20161027022420.GC31660@dtor-ws> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: y2038-bounces@lists.linaro.org Sender: "Y2038" To: Dmitry Torokhov Cc: Jiri Kosina , Arnd Bergmann , Hans de Goede , y2038 Mailman List , Linux Kernel Mailing List , Peter Hutterer , Benjamin Tissoires , linux-input@vger.kernel.org List-Id: linux-input@vger.kernel.org Pj4gc3RydWN0IHRpbWV2YWwgaXMgbm90IHkyMDM4IHNhZmUuCj4+IEFsbCB1c2FnZSBvZiB0aW1l dmFsIGluIHRoZSBrZXJuZWwgd2lsbCBiZSByZXBsYWNlZCBieQo+PiB5MjAzOCBzYWZlIHN0cnVj dHVyZXMuCj4+Cj4+IHN0cnVjdCBpbnB1dF9ldmVudCBtYWludGFpbnMgdGltZSBmb3IgZWFjaCBp bnB1dCBldmVudC4KPj4gUmVhbCB0aW1lIHRpbWVzdGFtcHMgYXJlIG5vdCBpZGVhbCBmb3IgaW5w dXQgYXMgdGhpcwo+PiB0aW1lIGNhbiBnbyBiYWNrd2FyZHMgYXMgbm90ZWQgaW4gdGhlIHBhdGNo IGE4MGI4M2I3YjgKPj4gYnkgSm9obiBTdHVsdHouIEhlbmNlLCBoYXZpbmcgdGhlIGlucHV0X2V2 ZW50LnRpbWUgZmllbGRzCj4+IG9ubHkgYmlnIGVub3VnaCBmb3IgbW9ub3RvbmljIGFuZCBib290 IHRpbWVzIGFyZQo+PiBzdWZmaWNpZW50Lgo+Pgo+PiBMZWF2ZSB0aGUgb3JpZ2luYWwgaW5wdXRf ZXZlbnQgYXMgaXMuIFRoaXMgaXMgdG8gbWFpbnRhaW4KPj4gYmFja3dhcmQgY29tcGF0aWJpbGl0 eSB3aXRoIGV4aXN0aW5nIHVzZXJzcGFjZSBpbnRlcmZhY2VzCj4+IHRoYXQgdXNlIGlucHV0X2V2 ZW50Lgo+PiBJbnRyb2R1Y2UgYSBuZXcgcmVwbGFjZW1lbnQgc3RydWN0IHJhd19pbnB1dF9ldmVu dC4KPj4gVGhpcyByZXBsYWNlcyB0aW1ldmFsIHdpdGggc3RydWN0IGlucHV0X3RpbWV2YWwuIFRo aXMgc3RydWN0dXJlCj4+IG1haW50YWlucyB0aW1lIGluIF9fa2VybmVsX3Vsb25nX3Qgb3IgY29t cGF0X3Vsb25nX3QgdG8gYWxsb3cKPj4gZm9yIGFyY2hpdGVjdHVyZXMgdG8gb3ZlcnJpZGUgdHlw ZXMgYXMgaW4gdGhlIGNhc2Ugb2YgeDMyLgo+Pgo+PiBUaGUgY2hhbmdlIHJlcXVpcmVzIGFueSB1 c2Vyc3BhY2UgdXRpbGl0aWVzIHJlYWRpbmcgb3Igd3JpdGluZwo+PiBmcm9tIGV2ZW50IG5vZGVz IHRvIHVwZGF0ZSB0aGVpciByZWFkaW5nIGZvcm1hdCB0byBtYXRjaAo+PiByYXdfaW5wdXRfZXZl bnQuIFRoZSBjaGFuZ2VzIHRvIHRoZSBwb3B1bGFyIGxpYnJhcmllcyB3aWxsIGJlCj4+IHBvc3Rl ZCBhbG9uZyB3aXRoIHRoZSBrZXJuZWwgY2hhbmdlcy4KPj4gVGhlIGRyaXZlciB2ZXJzaW9uIGlz IGFsc28gdXBkYXRlZCB0byByZWZsZWN0IHRoZSBjaGFuZ2UgaW4KPj4gZXZlbnQgZm9ybWF0Lgo+ Cj4gSWYgdXNlcnMgYXJlIGZvcmNlZCB0byB1cGRhdGUgdG8gYWRhcHQgdG8gdGhlIG5ldyBldmVu dCBmb3JtYXQsIHNob3VsZAo+IHdlIGNvbnNpZGVyIG1vcmUgcmFkaWNhbCBjaGFuZ2VzPyBGb3Ig ZXhhbXBsZSwgZG9lcyBpdCBtYWtlIHNlbnNlIHRvCj4gc2VuZCB0aW1lc3RhbXAgb24gZXZlcnkg ZXZlbnQ/IE1heWJlIHdlIHNob3VsZCBvbmx5IHNlbmQgaXQgb25jZSBwZXIKPiBldmVudCBwYWNr ZXQgKGJldHdlZW4gRVZfU1lOL1NZTl9SRVBPUlQpPyBXaGF0IGdyYW51bGFyaXR5IGRvIHdlIG5l ZWQ/Cj4gSXMgdGhlcmUgYW55dGhpbmcgZWxzZSBpbiBjdXJyZW50IHByb3RvY29sIHRoYXQgd2Un ZCBsaWtlIHRvIGNoYW5nZT8KCkkgZGlkIHNlZSB0aGUgdGhyZWFkIHdpdGggUGluZ2JvJ3MgcGF0 Y2hlcyB3aGVyZSB5b3UgaGFkIGEgc2ltaWxhciBjb21tZW50LgoKSSBzZWUgbXkgc2VyaWVzIGFz IGRlY291cGxpbmcgdGhlIGtlcm5lbCBpbnB1dCBldmVudCBmb3JtYXQgZnJvbSB0aGUKdXNlcnNw YWNlIGZvcm1hdC4KVGhlIGZvcm1hdHMgYWxzbyBhcmUgcmVhbGx5IHRoZSBzYW1lIHN0aWxsLgpD b3VsZCB0aGlzIGJlIGNvbnNpZGVyZWQgdGhlIGZpcnN0IHN0ZXAgdG93YXJkcyBjaGFuZ2luZyB0 aGUgcHJvdG9jb2w/CgpUaGUgcHJvdG9jb2wgY2hhbmdlcyBtaWdodCBuZWVkIG5ldyBpbnRlcmZh Y2VzIHRvIGJlIGRlZmluZWQgYmV0d2VlbiBsaWJyYXJpZXMuCkFuZCwgY291bGQgZW5kIHVwIGJl aW5nIGEgc3Vic3RhbnRpYWwgY2hhbmdlLgpXb3VsZCBhIHN0ZXAgYnkgc3RlcCBhcHByb2FjaCBt YWtlIHNlbnNlPwoKLURlZXBhCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fClkyMDM4IG1haWxpbmcgbGlzdApZMjAzOEBsaXN0cy5saW5hcm8ub3JnCmh0dHBz Oi8vbGlzdHMubGluYXJvLm9yZy9tYWlsbWFuL2xpc3RpbmZvL3kyMDM4Cg==