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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 E825AC433E6 for ; Mon, 15 Feb 2021 09:07:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9E25664E68 for ; Mon, 15 Feb 2021 09:07:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230108AbhBOJHL (ORCPT ); Mon, 15 Feb 2021 04:07:11 -0500 Received: from mail-40134.protonmail.ch ([185.70.40.134]:34397 "EHLO mail-40134.protonmail.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230063AbhBOJG5 (ORCPT ); Mon, 15 Feb 2021 04:06:57 -0500 Date: Mon, 15 Feb 2021 09:06:01 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=emersion.fr; s=protonmail3; t=1613379973; bh=2nAm6Q9p3kMTXLrc/9PsknifgDbenAAUOXq3KGVIrtw=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References:From; b=AgihlhiMBiKpn2AUSMU4MbjjTvrJBs+g1bQ2Z7b8VBvkxoiItg9javlL+V3ZfoiJg IeooACpUH4OVaTrX3hHe50R7sm6h7VarQsTDXwyUY0Kv2r0T8K2L7j6BN3BGh6YmFN PUlSgqUWc7yVU6DKZKu3NupB73Q44cDX7zsQhs/W7NO8/2MB231MTcFGSjaHuphS36 Lh6Fo5qoe2kWu5gZL9fnUkA5fFUgzM8+xnMEpFS/pw6coIuKaBSinCXUm/QS79liZU c7G7x2oaubgXNU9wYybPMmwYc+gxXHoVLzrLxg6VUtykma0fnggRK7xzshR7XzIso0 zXx+fQn+jz0+w== To: =?utf-8?Q?Christian_K=C3=B6nig?= From: Simon Ser Cc: linux-media , dri-devel , linaro-mm-sig@lists.linaro.org, lkml , "Sharma, Shashank" Reply-To: Simon Ser Subject: Re: DMA-buf and uncached system memory Message-ID: In-Reply-To: <91ff0bbb-ea3a-2663-3453-dea96ccd6dd8@amd.com> References: <91ff0bbb-ea3a-2663-3453-dea96ccd6dd8@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday, February 15th, 2021 at 9:58 AM, Christian K=C3=B6nig wrote: > we are currently working an Freesync and direct scan out from system > memory on AMD APUs in A+A laptops. > > On problem we stumbled over is that our display hardware needs to scan > out from uncached system memory and we currently don't have a way to > communicate that through DMA-buf. > > For our specific use case at hand we are going to implement something > driver specific, but the question is should we have something more > generic for this? > > After all the system memory access pattern is a PCIe extension and as > such something generic. Intel also needs uncached system memory if I'm not mistaken? Where are the buffers allocated? If GBM, then it needs to allocate memory t= hat can be scanned out if the USE_SCANOUT flag is set or if a scanout-capable modifier is picked. If this is about communicating buffer constraints between different compone= nts of the stack, there were a few proposals about it. The most recent one is [= 1]. Simon [1]: https://xdc2020.x.org/event/9/contributions/615/ 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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 46210C433E0 for ; Mon, 15 Feb 2021 09:06:19 +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 D0DCF60231 for ; Mon, 15 Feb 2021 09:06:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D0DCF60231 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=emersion.fr 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 31AF16E151; Mon, 15 Feb 2021 09:06:18 +0000 (UTC) Received: from mail-40134.protonmail.ch (mail-40134.protonmail.ch [185.70.40.134]) by gabe.freedesktop.org (Postfix) with ESMTPS id DDB446E150 for ; Mon, 15 Feb 2021 09:06:16 +0000 (UTC) Date: Mon, 15 Feb 2021 09:06:01 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=emersion.fr; s=protonmail3; t=1613379973; bh=2nAm6Q9p3kMTXLrc/9PsknifgDbenAAUOXq3KGVIrtw=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References:From; b=AgihlhiMBiKpn2AUSMU4MbjjTvrJBs+g1bQ2Z7b8VBvkxoiItg9javlL+V3ZfoiJg IeooACpUH4OVaTrX3hHe50R7sm6h7VarQsTDXwyUY0Kv2r0T8K2L7j6BN3BGh6YmFN PUlSgqUWc7yVU6DKZKu3NupB73Q44cDX7zsQhs/W7NO8/2MB231MTcFGSjaHuphS36 Lh6Fo5qoe2kWu5gZL9fnUkA5fFUgzM8+xnMEpFS/pw6coIuKaBSinCXUm/QS79liZU c7G7x2oaubgXNU9wYybPMmwYc+gxXHoVLzrLxg6VUtykma0fnggRK7xzshR7XzIso0 zXx+fQn+jz0+w== To: =?utf-8?Q?Christian_K=C3=B6nig?= From: Simon Ser Subject: Re: DMA-buf and uncached system memory Message-ID: In-Reply-To: <91ff0bbb-ea3a-2663-3453-dea96ccd6dd8@amd.com> References: <91ff0bbb-ea3a-2663-3453-dea96ccd6dd8@amd.com> MIME-Version: 1.0 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: , Reply-To: Simon Ser Cc: linaro-mm-sig@lists.linaro.org, "Sharma, Shashank" , lkml , dri-devel , linux-media Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" T24gTW9uZGF5LCBGZWJydWFyeSAxNXRoLCAyMDIxIGF0IDk6NTggQU0sIENocmlzdGlhbiBLw7Zu aWcgPGNocmlzdGlhbi5rb2VuaWdAYW1kLmNvbT4gd3JvdGU6Cgo+IHdlIGFyZSBjdXJyZW50bHkg d29ya2luZyBhbiBGcmVlc3luYyBhbmQgZGlyZWN0IHNjYW4gb3V0IGZyb20gc3lzdGVtCj4gbWVt b3J5IG9uIEFNRCBBUFVzIGluIEErQSBsYXB0b3BzLgo+Cj4gT24gcHJvYmxlbSB3ZSBzdHVtYmxl ZCBvdmVyIGlzIHRoYXQgb3VyIGRpc3BsYXkgaGFyZHdhcmUgbmVlZHMgdG8gc2Nhbgo+IG91dCBm cm9tIHVuY2FjaGVkIHN5c3RlbSBtZW1vcnkgYW5kIHdlIGN1cnJlbnRseSBkb24ndCBoYXZlIGEg d2F5IHRvCj4gY29tbXVuaWNhdGUgdGhhdCB0aHJvdWdoIERNQS1idWYuCj4KPiBGb3Igb3VyIHNw ZWNpZmljIHVzZSBjYXNlIGF0IGhhbmQgd2UgYXJlIGdvaW5nIHRvIGltcGxlbWVudCBzb21ldGhp bmcKPiBkcml2ZXIgc3BlY2lmaWMsIGJ1dCB0aGUgcXVlc3Rpb24gaXMgc2hvdWxkIHdlIGhhdmUg c29tZXRoaW5nIG1vcmUKPiBnZW5lcmljIGZvciB0aGlzPwo+Cj4gQWZ0ZXIgYWxsIHRoZSBzeXN0 ZW0gbWVtb3J5IGFjY2VzcyBwYXR0ZXJuIGlzIGEgUENJZSBleHRlbnNpb24gYW5kIGFzCj4gc3Vj aCBzb21ldGhpbmcgZ2VuZXJpYy4KCkludGVsIGFsc28gbmVlZHMgdW5jYWNoZWQgc3lzdGVtIG1l bW9yeSBpZiBJJ20gbm90IG1pc3Rha2VuPwoKV2hlcmUgYXJlIHRoZSBidWZmZXJzIGFsbG9jYXRl ZD8gSWYgR0JNLCB0aGVuIGl0IG5lZWRzIHRvIGFsbG9jYXRlIG1lbW9yeSB0aGF0CmNhbiBiZSBz Y2FubmVkIG91dCBpZiB0aGUgVVNFX1NDQU5PVVQgZmxhZyBpcyBzZXQgb3IgaWYgYSBzY2Fub3V0 LWNhcGFibGUKbW9kaWZpZXIgaXMgcGlja2VkLgoKSWYgdGhpcyBpcyBhYm91dCBjb21tdW5pY2F0 aW5nIGJ1ZmZlciBjb25zdHJhaW50cyBiZXR3ZWVuIGRpZmZlcmVudCBjb21wb25lbnRzCm9mIHRo ZSBzdGFjaywgdGhlcmUgd2VyZSBhIGZldyBwcm9wb3NhbHMgYWJvdXQgaXQuIFRoZSBtb3N0IHJl Y2VudCBvbmUgaXMgWzFdLgoKU2ltb24KClsxXTogaHR0cHM6Ly94ZGMyMDIwLngub3JnL2V2ZW50 LzkvY29udHJpYnV0aW9ucy82MTUvCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fCmRyaS1kZXZlbCBtYWlsaW5nIGxpc3QKZHJpLWRldmVsQGxpc3RzLmZyZWVk ZXNrdG9wLm9yZwpodHRwczovL2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9tYWlsbWFuL2xpc3RpbmZv L2RyaS1kZXZlbAo=