From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: [PATCH 3/3] drm: Add CRTC_GET_SEQUENCE and CRTC_QUEUE_SEQUENCE ioctls Date: Thu, 6 Jul 2017 20:59:40 +0300 Message-ID: <20170706175940.GA12629@intel.com> References: <20170705221013.27940-1-keithp@keithp.com> <20170705221013.27940-4-keithp@keithp.com> <20170706075313.bn2exiklfabgc25t@phenom.ffwll.local> <20170706101604.GY12629@intel.com> <20170706140805.GZ12629@intel.com> <86tw2pbkcn.fsf@keithp.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 69AC96E1DC for ; Thu, 6 Jul 2017 17:59:44 +0000 (UTC) Content-Disposition: inline In-Reply-To: <86tw2pbkcn.fsf@keithp.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Keith Packard Cc: Dave Airlie , dri-devel , Linux Kernel Mailing List List-Id: dri-devel@lists.freedesktop.org T24gVGh1LCBKdWwgMDYsIDIwMTcgYXQgMDk6Mjg6NDBBTSAtMDcwMCwgS2VpdGggUGFja2FyZCB3 cm90ZToKPiBWaWxsZSBTeXJqw6Rsw6QgPHZpbGxlLnN5cmphbGFAbGludXguaW50ZWwuY29tPiB3 cml0ZXM6Cj4gCj4gPiBNYXliZSwgb3IgbWF5YmUgd2Ugd2FudCB0byB0dXJuIHRoZSBpbnRlcnJ1 cHQgb24gaW4gdGhhdCBjYXNlPyBUaGF0J3MKPiA+IHdoYXQgdGhlIG9sZCBpb2N0bCBkb2VzLgo+ IAo+IFRoYXQncyB3aGF0IEkgc3VnZ2VzdGVkIGluIG15IHJlcGx5IHRvIERhbmllbCdzIHJldmll dy4gRXZlbiBpZiB3ZSBhZGQKPiB0aGUgYWNjdXJhdGUgZnVuY3Rpb24sIHdlJ2xsIHN0aWxsIG5l ZWQgdGhlIGludGVycnVwdC1lbmFibGUgY2FzZSBhcyBhCj4gZmFsbGJhY2sgZm9yIGRyaXZlcnMg d2hpY2ggZG9uJ3Qgc3VwcG9ydCB0aGUgYWNjdXJhdGUgcGF0aCwgcmlnaHQ/CgpUQkggSSBkaWRu J3QgZXZlbiBjb25zaWRlciB0aGF0IGNhc2UsIGJ1dCB5ZWFoIG1ha2VzIHNlbnNlLiBPdGhlcndp c2UKdGhlIGNvdW50ZXIgd29uJ3Qgc3RhcnQgdG8gdGljayBhbmQgdGhlIHJlc3VsdCBvZiB0aGUg cXVlcnkgaXMgcHJldHR5Cm11Y2ggdXNlbGVzcy4KCkkgd2FzIG1vc3RseSB0aGlua2luZyBvZiB0 aGUgJ3NlcSA9IHF1ZXJ5KCk7IHdhaXQoc2VxICsgbik7JyBwYXR0ZXJuCndoZXJlIHdlIGNhbiBh dm9pZCBkb2luZyB0aGUgZnVsbCB1cGRhdGUgbW9yZSB0aGFuIG9uY2UgaWYgd2UgZW5hYmxlCnRo ZSBpbnRlcnJ1cHQgYWxyZWFkeSBkdXJpbmcgdGhlIHF1ZXJ5LgoKLS0gClZpbGxlIFN5cmrDpGzD pApJbnRlbCBPVEMKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X18KZHJpLWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3Jn Cmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVs Cg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752093AbdGFR7v (ORCPT ); Thu, 6 Jul 2017 13:59:51 -0400 Received: from mga02.intel.com ([134.134.136.20]:57624 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751956AbdGFR7u (ORCPT ); Thu, 6 Jul 2017 13:59:50 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.40,318,1496127600"; d="scan'208";a="108035611" Date: Thu, 6 Jul 2017 20:59:40 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Keith Packard Cc: Daniel Vetter , Linux Kernel Mailing List , Dave Airlie , dri-devel Subject: Re: [PATCH 3/3] drm: Add CRTC_GET_SEQUENCE and CRTC_QUEUE_SEQUENCE ioctls Message-ID: <20170706175940.GA12629@intel.com> References: <20170705221013.27940-1-keithp@keithp.com> <20170705221013.27940-4-keithp@keithp.com> <20170706075313.bn2exiklfabgc25t@phenom.ffwll.local> <20170706101604.GY12629@intel.com> <20170706140805.GZ12629@intel.com> <86tw2pbkcn.fsf@keithp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <86tw2pbkcn.fsf@keithp.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 06, 2017 at 09:28:40AM -0700, Keith Packard wrote: > Ville Syrjälä writes: > > > Maybe, or maybe we want to turn the interrupt on in that case? That's > > what the old ioctl does. > > That's what I suggested in my reply to Daniel's review. Even if we add > the accurate function, we'll still need the interrupt-enable case as a > fallback for drivers which don't support the accurate path, right? TBH I didn't even consider that case, but yeah makes sense. Otherwise the counter won't start to tick and the result of the query is pretty much useless. I was mostly thinking of the 'seq = query(); wait(seq + n);' pattern where we can avoid doing the full update more than once if we enable the interrupt already during the query. -- Ville Syrjälä Intel OTC