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=-5.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 488C5CA9EA0 for ; Tue, 22 Oct 2019 14:03:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 260CE21872 for ; Tue, 22 Oct 2019 14:03:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388960AbfJVODE (ORCPT ); Tue, 22 Oct 2019 10:03:04 -0400 Received: from lb3-smtp-cloud8.xs4all.net ([194.109.24.29]:54489 "EHLO lb3-smtp-cloud8.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387965AbfJVODD (ORCPT ); Tue, 22 Oct 2019 10:03:03 -0400 Received: from [IPv6:2001:420:44c1:2577:31:9f59:b53f:5d72] ([IPv6:2001:420:44c1:2577:31:9f59:b53f:5d72]) by smtp-cloud8.xs4all.net with ESMTPA id MukTi3IXtPduvMukWiMkLM; Tue, 22 Oct 2019 16:03:01 +0200 Subject: Re: [PATCH v8 3/3] media: cedrus: Add HEVC/H.265 decoding support To: Paul Kocialkowski Cc: Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-sunxi@googlegroups.com, Chen-Yu Tsai , Maxime Ripard , Ezequiel Garcia , Tomasz Figa , Nicolas Dufresne , Jernej Skrabec , Jonas Karlman , Thomas Petazzoni References: <20190927143411.141526-1-paul.kocialkowski@bootlin.com> <20190927143411.141526-4-paul.kocialkowski@bootlin.com> <20191017095751.5a229051@coco.lan> <20191022124012.GD2651@aptenodytes> <20191022131751.GE2651@aptenodytes> <62ddccd3-38c0-89c5-7f0c-35f24494c3f9@xs4all.nl> <20191022140129.GA1926725@aptenodytes> From: Hans Verkuil Message-ID: <345a6781-a5b3-1408-40ec-580873720c4a@xs4all.nl> Date: Tue, 22 Oct 2019 16:02:57 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20191022140129.GA1926725@aptenodytes> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4wfLyToBbJkvoNRLhYqBvZHVXfIm7iukgHkajVmC/txXYqaReY4el4wR3BxG5BTgxtiScGgBnV0kxhH6kDr/OEW3KJ+v+YsODAMwe5yEeEtS+FgbsHq7dV fdMG0VGNqYIhwjH7J7Sb+mXFSLzj4uPkGVG4X/JcZOw+OeFPvLRkzs5wJxPWAuzxPlOqry9K8/FLndsCmhzA0hYSRp/x7bP7eGayeRjAN7wu9urRBuySNMAT rpTuaQggdjanULe0u/fQM+fW9lb7FPpkjNuLW20PZ3ZCjRDSOdPEvMnmFWbsH3oGnI/KfL45Gi99Jdvvsn5LhBuiCxtz2/uiLE8ZTTuEPMdOPI8NWS14W+Sd OfoivH1DiUS0VaLSAsSbfZ0iM/q/LUE9JuCwlCWLZcVmEXv0hZ+IJzmMUiTIP0GPdwEYU3JXPstdFkz1oXZmizJhk7BzABSrYr3PM8q2I08RmiB6zgRdovHk lS27pzKhvOA4nbPJQDskKROYHec/bUkcDAs4xo0spMXqB70ExtmEnQpUq7oCQXCbsmvvv5SaYgnnOePA0YI3ngH2mlRuJrebfwZrJ8vPF4UHPtQT+dEGSpWw HpuMzANUMUE0Puthk1YVByV9ER72/ENKKACHrdmCiU89opg6jSk+365tsEvgse/moOebrKO/EyhqyTOUn5T3cTSXo6dTLb8ZCko9xT4WTOhx5obzgZcMpUzy SOq+0knuWhd4idM5xZhC/M2gEmyV+tPY Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/22/19 4:01 PM, Paul Kocialkowski wrote: > Hi, > > On Tue 22 Oct 19, 15:37, Hans Verkuil wrote: >> On 10/22/19 3:17 PM, Paul Kocialkowski wrote: >>> Hi again, >>> >>> On Tue 22 Oct 19, 14:40, Paul Kocialkowski wrote: >>>> Hi Mauro and thanks for the review, >>>> >>>> On Thu 17 Oct 19, 09:57, Mauro Carvalho Chehab wrote: >>>>> Em Fri, 27 Sep 2019 16:34:11 +0200 >>>>> Paul Kocialkowski escreveu: >>>>> >>>>>> This introduces support for HEVC/H.265 to the Cedrus VPU driver, with >>>>>> both uni-directional and bi-directional prediction modes supported. >>>>>> >>>>>> Field-coded (interlaced) pictures, custom quantization matrices and >>>>>> 10-bit output are not supported at this point. >>>>>> >>>>>> Signed-off-by: Paul Kocialkowski >>>>>> --- >>>>> >>>>> ... >>>>> >>>>>> + unsigned int ctb_size_luma = >>>>>> + 1 << log2_max_luma_coding_block_size; >>>>> >>>>> Shifts like this is a little scary. "1" constant is signed. So, if >>>>> log2_max_luma_coding_block_size is 31, the above logic has undefined >>>>> behavior. Different archs and C compilers may handle it on different >>>>> ways. >>>> >>>> I wasn't aware that it was the case, thanks for bringing this to light! >>>> I'll make it 1UL then. >>>> >>>>>> +#define VE_DEC_H265_LOW_ADDR_PRIMARY_CHROMA(a) \ >>>>>> + (((a) << 24) & GENMASK(31, 24)) >>>>> >>>>> Same applies here and on other similar macros. You need to enforce >>>>> (a) to be unsigned, as otherwise the behavior is undefined. >>>>> >>>>> Btw, this is a recurrent pattern on this file. I would define a >>>>> macro, e. g. something like: >>>>> >>>>> #define MASK_BITS_AND_SHIFT(v, high, low) \ >>>>> ((UL(v) << low) & GENMASK(high, low)) >>>>> >>>>> And use it for all similar patterns here. >>>> >>>> Sounds good! I find that the reverse wording (SHIFT_AND_MASK_BITS) would be >>>> a bit more explicit since the shift happens prior to the mask. >>> >>> Apparently the UL(v) macro just appends UL to v in preprocessor, so it won't >>> work with anything else than direct integers. >>> >>> I'll replace it with a (unsigned long) cast, that seems to do the job. >> >> Shouldn't that be a (u32) cast? Since this is used with 32 bit registers? > > This would work for cedrus, but I think that what Mauro had in mind was to > migrate this macro to linux/bits.h, where everthing else (including GENMASK) > is apparently defined in terms of unsigned long and not types with explicit > numbers of bits. So I find it more consistent to go with unsigned long. > > In our case, 64-bit platforms that use cedrus would calculate the macro on > 64 bits and use it in 32-bit variables. Since we're never masking beyond the > lower 32 bits, I don't see how things could go wrong and the situation looks > fairly similar to the use of GENMASK in similar conditions. > > Does that sound right to you or am I missing something here? Ah, OK. Fair enough. Regards, Hans > > Cheers, > > Paul > >> Regards, >> >> Hans >> >>> >>> Cheers, >>> >>> Paul >>> >>>> Also we probably need to have parenthesis around "low", right? >>>> >>>>> The best would be to include such macro at linux/bits.h, although some >>>>> upstream discussion is required. >>>>> >>>>> So, for now, let's add it at this header file, but work upstream >>>>> to have it merged there. >>>> >>>> Understood, I'll include it in that header for now and send a separate patch >>>> for inclusion in linux/bits.h (apparently the preprocessor doesn't care about >>>> redefinitions so we can just remove the cedrus fashion once the common one is >>>> in). >>>> >>>> What do you think? >>>> >>>> Cheers, >>>> >>>> Paul >>> >>> >>> >> >