From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 882DFC433DB for ; Wed, 27 Jan 2021 22:07:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4332B64DCD for ; Wed, 27 Jan 2021 22:07:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233215AbhA0WHb (ORCPT ); Wed, 27 Jan 2021 17:07:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234345AbhA0WH2 (ORCPT ); Wed, 27 Jan 2021 17:07:28 -0500 Received: from mail-lf1-x129.google.com (mail-lf1-x129.google.com [IPv6:2a00:1450:4864:20::129]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C6FBBC061573 for ; Wed, 27 Jan 2021 14:06:47 -0800 (PST) Received: by mail-lf1-x129.google.com with SMTP id m22so4875220lfg.5 for ; Wed, 27 Jan 2021 14:06:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=w4UzLpV8aeIvghlGpXTYskzYBALzwvbsPewbvs0UWB0=; b=uNq31EBc1MHV0VcDHLVub0/i7Z0pS7OB6tHn+5pTo84LYs/r3KMtS4mMF8gIz4LLFr zvY7T5uSQzlMCMno0ehRnLiXn7tlOMOinIuzEBj2Fj8lu6Wgsnr0tnDFL508TuNCyeEC WULq60W87WJpMkIrstv+cRNPep7QZDxwOLv/tPzJaQuE51hllbFhGDoZ/ttRseH1ncZd B74YRxJz9ClvpUST0oi6e3mQxj3HhrznXBzfV+ZhPuOUkj/Emk/CHYSq1HqjkU5vwiha V2jCjSQotlcN6VWu+3A6Z0IHJkKLz4LhAEMTYb0sftPB+FOYQu/Js/3ljPEMN/4NpMOI 5Chg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=w4UzLpV8aeIvghlGpXTYskzYBALzwvbsPewbvs0UWB0=; b=L69aTphQCx4K1rp6rW6uaxvrtifEf9gSUvJwK/YdmcluPfiKTyLhUEJHcMfQApOqUc ygGylVMA912mBHq0YIsu1bGVJrbumA7S+yIdVo6myGaJkgUUoo1Fko7cFwP2RGjCUS/x 4oPi7r6vGOr5vUwnRQnRvPhRkMBoKzXXRaB2hGFDyPYvxq9fvNrORKIGfyIuvGUIkILF glsa1HSBWE/bfKW92j1SaT/bX1p0/KeqHP6RwuSmKVFFOAMIG//xR6muNcK5pV54uG5h 9oHigxPYLIqlZPuzEqVEykRqucobXADMB45p76wmiwrGpir9isUP6vZsAyg71LThbWrA mQcg== X-Gm-Message-State: AOAM532wi0N13oBioEf+JubdObbuFUqdEMvmQLKNlHVtTrU2PxrGvoMf B2t/h4/u6VVolmCJcRwOBR4= X-Google-Smtp-Source: ABdhPJw1hofd9fLlol38qlFI48ZZMLmBA4ldPwxc4kQMLljkdKlyBtH4c1m0aYzMiMFzZG9cLI0u3A== X-Received: by 2002:a05:6512:224f:: with SMTP id i15mr6174387lfu.545.1611785206351; Wed, 27 Jan 2021 14:06:46 -0800 (PST) Received: from ?IPv6:2a00:1370:814d:ea25:a10:76ff:fe69:21b6? ([2a00:1370:814d:ea25:a10:76ff:fe69:21b6]) by smtp.googlemail.com with ESMTPSA id 24sm848983lfy.32.2021.01.27.14.06.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 27 Jan 2021 14:06:45 -0800 (PST) Subject: Re: [PATCH v5 00/21] Host1x/TegraDRM UAPI To: Mikko Perttunen , Mikko Perttunen , thierry.reding@gmail.com, jonathanh@nvidia.com, airlied@linux.ie, daniel@ffwll.ch Cc: linux-tegra@vger.kernel.org, dri-devel@lists.freedesktop.org, talho@nvidia.com, bhuntsman@nvidia.com References: <20210111130019.3515669-1-mperttunen@nvidia.com> <2f999b6d-d781-503a-78f4-d444bce72c58@kapsi.fi> <638c1aeb-921b-0ea2-5258-16c6d3183306@gmail.com> <9f755e95-97fc-4f57-5e8d-426af589c857@kapsi.fi> From: Dmitry Osipenko Message-ID: <007d123f-526a-c68a-3c52-aba165172cdf@gmail.com> Date: Thu, 28 Jan 2021 01:06:45 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.2 MIME-Version: 1.0 In-Reply-To: <9f755e95-97fc-4f57-5e8d-426af589c857@kapsi.fi> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-tegra@vger.kernel.org 28.01.2021 00:57, Mikko Perttunen пишет: > > > On 1/27/21 11:26 PM, Dmitry Osipenko wrote: >> 26.01.2021 05:45, Mikko Perttunen пишет: >>>> 5. The hardware state of sync points should be reset when sync point is >>>> requested, not when host1x driver is initialized. >>> >>> This may be doable, but I don't think it is critical for this UAPI, so >>> let's consider it after this series. >>> >>> The userspace should anyway not be able to assume the initial value of >>> the syncpoint upon allocation. The kernel should set it to some high >>> value to catch any issues related to wraparound. >> >> This is critical because min != max when sync point is requested. > > That I would just consider a bug, and it can be fixed. But it's > orthogonal to whether the value gets reset every time the syncpoint is > allocated. > >> >>> Also, this makes code more complicated since it now needs to ensure all >>> waits on the syncpoint have completed before freeing the syncpoint, >>> which can be nontrivial e.g. if the waiter is in a different virtual >>> machine or some other device connected via PCIe (a real usecase). >> >> It sounds to me that these VM sync points should be treated very >> separately from a generic sync points, don't you think so? Let's not mix >> them and get the generic sync points usable first. >> > > They are not special in any way, I'm just referring to cases where the > waiter (consumer) is remote. The allocator of the syncpoint (producer) > doesn't necessarily even need to know about it. The same concern is > applicable within a single VM, or single application as well. Just > putting out the point that this is something that needs to be taken care > of if we were to reset the value. Will kernel driver know that it deals with a VM sync point? Will it be possible to get a non-VM sync point explicitly? If driver knows that it deals with a VM sync point, then we can treat it specially, avoiding the reset and etc. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B499EC433E0 for ; Thu, 28 Jan 2021 08:17:51 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5ECE46146D for ; Thu, 28 Jan 2021 08:17:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5ECE46146D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 687BE6E943; Thu, 28 Jan 2021 08:16:50 +0000 (UTC) Received: from mail-lf1-x12b.google.com (mail-lf1-x12b.google.com [IPv6:2a00:1450:4864:20::12b]) by gabe.freedesktop.org (Postfix) with ESMTPS id EB05E89F08 for ; Wed, 27 Jan 2021 22:06:47 +0000 (UTC) Received: by mail-lf1-x12b.google.com with SMTP id a12so4901722lfb.1 for ; Wed, 27 Jan 2021 14:06:47 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=w4UzLpV8aeIvghlGpXTYskzYBALzwvbsPewbvs0UWB0=; b=uNq31EBc1MHV0VcDHLVub0/i7Z0pS7OB6tHn+5pTo84LYs/r3KMtS4mMF8gIz4LLFr zvY7T5uSQzlMCMno0ehRnLiXn7tlOMOinIuzEBj2Fj8lu6Wgsnr0tnDFL508TuNCyeEC WULq60W87WJpMkIrstv+cRNPep7QZDxwOLv/tPzJaQuE51hllbFhGDoZ/ttRseH1ncZd B74YRxJz9ClvpUST0oi6e3mQxj3HhrznXBzfV+ZhPuOUkj/Emk/CHYSq1HqjkU5vwiha V2jCjSQotlcN6VWu+3A6Z0IHJkKLz4LhAEMTYb0sftPB+FOYQu/Js/3ljPEMN/4NpMOI 5Chg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=w4UzLpV8aeIvghlGpXTYskzYBALzwvbsPewbvs0UWB0=; b=XHLrSwD3MzHZdmjDNB+FNiQakBVTGgpWcKtagz6gaQ6v//zdNCvoflx5LJLGYt3JTb fsoVDFSiyTJePQ0Fd1Y9VdjdVPzxMAv/sBLOuC7kiH3irmluUHpyXBKQj1JAO5PCihpb OA5MH0ZkG4wBdvhkmnf9m3E0RCmASqwrsNDoSq2FyebYcZ9dGW6QpWRz83iHpSxGuCJe J0WxH/tWghDzuHiV0jZMNOyU03BfaV99AB8japHrDgSrlyV2EVyBYpt5cZDZm4AUs7s9 ydAT2+cnhv9Z9Uucd7PkMuGleLUwp+2WCjCptfpFrP5Ju46i6mGkZjuDerGB0LLuCvRB XukA== X-Gm-Message-State: AOAM532bMUvs7/P9Cvf4QOz9eYHLIky11MQaS+Kl3VerIcPS1/DIiOoL CmDOsZN+4UNMO4QEfV4jUJs9YNwYYjc= X-Google-Smtp-Source: ABdhPJw1hofd9fLlol38qlFI48ZZMLmBA4ldPwxc4kQMLljkdKlyBtH4c1m0aYzMiMFzZG9cLI0u3A== X-Received: by 2002:a05:6512:224f:: with SMTP id i15mr6174387lfu.545.1611785206351; Wed, 27 Jan 2021 14:06:46 -0800 (PST) Received: from ?IPv6:2a00:1370:814d:ea25:a10:76ff:fe69:21b6? ([2a00:1370:814d:ea25:a10:76ff:fe69:21b6]) by smtp.googlemail.com with ESMTPSA id 24sm848983lfy.32.2021.01.27.14.06.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 27 Jan 2021 14:06:45 -0800 (PST) Subject: Re: [PATCH v5 00/21] Host1x/TegraDRM UAPI To: Mikko Perttunen , Mikko Perttunen , thierry.reding@gmail.com, jonathanh@nvidia.com, airlied@linux.ie, daniel@ffwll.ch References: <20210111130019.3515669-1-mperttunen@nvidia.com> <2f999b6d-d781-503a-78f4-d444bce72c58@kapsi.fi> <638c1aeb-921b-0ea2-5258-16c6d3183306@gmail.com> <9f755e95-97fc-4f57-5e8d-426af589c857@kapsi.fi> From: Dmitry Osipenko Message-ID: <007d123f-526a-c68a-3c52-aba165172cdf@gmail.com> Date: Thu, 28 Jan 2021 01:06:45 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.4.2 MIME-Version: 1.0 In-Reply-To: <9f755e95-97fc-4f57-5e8d-426af589c857@kapsi.fi> Content-Language: en-US X-Mailman-Approved-At: Thu, 28 Jan 2021 08:15:35 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-tegra@vger.kernel.org, talho@nvidia.com, bhuntsman@nvidia.com, dri-devel@lists.freedesktop.org Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" MjguMDEuMjAyMSAwMDo1NywgTWlra28gUGVydHR1bmVuINC/0LjRiNC10YI6Cj4gCj4gCj4gT24g MS8yNy8yMSAxMToyNiBQTSwgRG1pdHJ5IE9zaXBlbmtvIHdyb3RlOgo+PiAyNi4wMS4yMDIxIDA1 OjQ1LCBNaWtrbyBQZXJ0dHVuZW4g0L/QuNGI0LXRgjoKPj4+PiA1LiBUaGUgaGFyZHdhcmUgc3Rh dGUgb2Ygc3luYyBwb2ludHMgc2hvdWxkIGJlIHJlc2V0IHdoZW4gc3luYyBwb2ludCBpcwo+Pj4+ IHJlcXVlc3RlZCwgbm90IHdoZW4gaG9zdDF4IGRyaXZlciBpcyBpbml0aWFsaXplZC4KPj4+Cj4+ PiBUaGlzIG1heSBiZSBkb2FibGUsIGJ1dCBJIGRvbid0IHRoaW5rIGl0IGlzIGNyaXRpY2FsIGZv ciB0aGlzIFVBUEksIHNvCj4+PiBsZXQncyBjb25zaWRlciBpdCBhZnRlciB0aGlzIHNlcmllcy4K Pj4+Cj4+PiBUaGUgdXNlcnNwYWNlIHNob3VsZCBhbnl3YXkgbm90IGJlIGFibGUgdG8gYXNzdW1l IHRoZSBpbml0aWFsIHZhbHVlIG9mCj4+PiB0aGUgc3luY3BvaW50IHVwb24gYWxsb2NhdGlvbi4g VGhlIGtlcm5lbCBzaG91bGQgc2V0IGl0IHRvIHNvbWUgaGlnaAo+Pj4gdmFsdWUgdG8gY2F0Y2gg YW55IGlzc3VlcyByZWxhdGVkIHRvIHdyYXBhcm91bmQuCj4+Cj4+IFRoaXMgaXMgY3JpdGljYWwg YmVjYXVzZSBtaW4gIT0gbWF4IHdoZW4gc3luYyBwb2ludCBpcyByZXF1ZXN0ZWQuCj4gCj4gVGhh dCBJIHdvdWxkIGp1c3QgY29uc2lkZXIgYSBidWcsIGFuZCBpdCBjYW4gYmUgZml4ZWQuIEJ1dCBp dCdzCj4gb3J0aG9nb25hbCB0byB3aGV0aGVyIHRoZSB2YWx1ZSBnZXRzIHJlc2V0IGV2ZXJ5IHRp bWUgdGhlIHN5bmNwb2ludCBpcwo+IGFsbG9jYXRlZC4KPiAKPj4KPj4+IEFsc28sIHRoaXMgbWFr ZXMgY29kZSBtb3JlIGNvbXBsaWNhdGVkIHNpbmNlIGl0IG5vdyBuZWVkcyB0byBlbnN1cmUgYWxs Cj4+PiB3YWl0cyBvbiB0aGUgc3luY3BvaW50IGhhdmUgY29tcGxldGVkIGJlZm9yZSBmcmVlaW5n IHRoZSBzeW5jcG9pbnQsCj4+PiB3aGljaCBjYW4gYmUgbm9udHJpdmlhbCBlLmcuIGlmIHRoZSB3 YWl0ZXIgaXMgaW4gYSBkaWZmZXJlbnQgdmlydHVhbAo+Pj4gbWFjaGluZSBvciBzb21lIG90aGVy IGRldmljZSBjb25uZWN0ZWQgdmlhIFBDSWUgKGEgcmVhbCB1c2VjYXNlKS4KPj4KPj4gSXQgc291 bmRzIHRvIG1lIHRoYXQgdGhlc2UgVk0gc3luYyBwb2ludHMgc2hvdWxkIGJlIHRyZWF0ZWQgdmVy eQo+PiBzZXBhcmF0ZWx5IGZyb20gYSBnZW5lcmljIHN5bmMgcG9pbnRzLCBkb24ndCB5b3UgdGhp bmsgc28/IExldCdzIG5vdCBtaXgKPj4gdGhlbSBhbmQgZ2V0IHRoZSBnZW5lcmljIHN5bmMgcG9p bnRzIHVzYWJsZSBmaXJzdC4KPj4KPiAKPiBUaGV5IGFyZSBub3Qgc3BlY2lhbCBpbiBhbnkgd2F5 LCBJJ20ganVzdCByZWZlcnJpbmcgdG8gY2FzZXMgd2hlcmUgdGhlCj4gd2FpdGVyIChjb25zdW1l cikgaXMgcmVtb3RlLiBUaGUgYWxsb2NhdG9yIG9mIHRoZSBzeW5jcG9pbnQgKHByb2R1Y2VyKQo+ IGRvZXNuJ3QgbmVjZXNzYXJpbHkgZXZlbiBuZWVkIHRvIGtub3cgYWJvdXQgaXQuIFRoZSBzYW1l IGNvbmNlcm4gaXMKPiBhcHBsaWNhYmxlIHdpdGhpbiBhIHNpbmdsZSBWTSwgb3Igc2luZ2xlIGFw cGxpY2F0aW9uIGFzIHdlbGwuIEp1c3QKPiBwdXR0aW5nIG91dCB0aGUgcG9pbnQgdGhhdCB0aGlz IGlzIHNvbWV0aGluZyB0aGF0IG5lZWRzIHRvIGJlIHRha2VuIGNhcmUKPiBvZiBpZiB3ZSB3ZXJl IHRvIHJlc2V0IHRoZSB2YWx1ZS4KCldpbGwga2VybmVsIGRyaXZlciBrbm93IHRoYXQgaXQgZGVh bHMgd2l0aCBhIFZNIHN5bmMgcG9pbnQ/CgpXaWxsIGl0IGJlIHBvc3NpYmxlIHRvIGdldCBhIG5v bi1WTSBzeW5jIHBvaW50IGV4cGxpY2l0bHk/CgpJZiBkcml2ZXIga25vd3MgdGhhdCBpdCBkZWFs cyB3aXRoIGEgVk0gc3luYyBwb2ludCwgdGhlbiB3ZSBjYW4gdHJlYXQgaXQKc3BlY2lhbGx5LCBh dm9pZGluZyB0aGUgcmVzZXQgYW5kIGV0Yy4KX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX18KZHJpLWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMu ZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlz dGluZm8vZHJpLWRldmVsCg==