From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mailout4.w1.samsung.com ([210.118.77.14]:45958 "EHLO mailout4.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752133AbcEXN6w (ORCPT ); Tue, 24 May 2016 09:58:52 -0400 Subject: Re: [PATCH 1/2] drm/exynos: g2d: Add support for old S5Pv210 type To: Tobias Jakobi , Inki Dae , Joonyoung Shim , Seung-Woo Kim , Kyungmin Park , David Airlie , Kukjin Kim , Mauro Carvalho Chehab , Marek Szyprowski , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-media@vger.kernel.org References: <1464096493-13378-1-git-send-email-k.kozlowski@samsung.com> <57445BE5.7060702@math.uni-bielefeld.de> Cc: Bartlomiej Zolnierkiewicz , Kamil Debski From: Krzysztof Kozlowski Message-id: <57445E16.90301@samsung.com> Date: Tue, 24 May 2016 15:58:46 +0200 MIME-version: 1.0 In-reply-to: <57445BE5.7060702@math.uni-bielefeld.de> Content-type: text/plain; charset=windows-1252 Content-transfer-encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 05/24/2016 03:49 PM, Tobias Jakobi wrote: > Hello Krzysztof, > > are you sure that these are the only differences. Because AFAIK there > are quite a few more: > - DMA submission of commands > - blend mode / rounding > - solid fill > - YCrCb support > - and probably more > > One would need to add least split the command list parser into a v3 and > v41 version to accomodate for the differences. In fact userspace/libdrm > would need to know which hw type it currently uses, but you currently > always return 4.1 in the corresponding ioctl. Eh, so probably my patch does not cover fully the support for v3 G2D. I looked mostly at the differences between v3 and v4 in the s5p-g2d driver itself. However you are right that this might be not sufficient because exynos-g2d moved forward and is different than s5p-g2d. > Krzysztof Kozlowski wrote: >> The non-DRM s5p-g2d driver supports two versions of G2D: v3.0 on >> S5Pv210 and v4.x on Exynos 4x12 (or newer). The driver for 3.0 device >> version is doing two things differently: >> 1. Before starting the render process, it invalidates caches (pattern, >> source buffer and mask buffer). Cache control is not present on v4.x >> device. >> 2. Scalling is done through StretchEn command (in BITBLT_COMMAND_REG >> register) instead of SRC_SCALE_CTRL_REG as in v4.x. However the >> exynos_drm_g2d driver does not implement the scalling so this >> difference can be eliminated. > Huh? Where did you get this from? Scaling works with the DRM driver. I was looking for the usage of scaling reg (as there is no scaling command). How the scaling is implemented then? Thanks for feedback! Best regards, Krzysztof