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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 27CE1C77B78 for ; Wed, 3 May 2023 17:35:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229836AbjECRe6 (ORCPT ); Wed, 3 May 2023 13:34:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33972 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229460AbjECRez (ORCPT ); Wed, 3 May 2023 13:34:55 -0400 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 890528F; Wed, 3 May 2023 10:34:52 -0700 (PDT) Received: from pps.filterd (m0279866.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 343GcDSb010737; Wed, 3 May 2023 17:34:44 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=qcppdkim1; bh=2SLyxb/oLFHe3Ff3BXtyoEm91MUW65yTTYRI3lRrWgE=; b=g34fVGZKG76Pp+sTgeZOTleEZXZjGS1NVsJf88NDukLEGQLUYpt5McGdsgJ+0XwTA13o yIToF6PsZSn1yGcyLa+9KCzsCY2D22Y54p6M7XXQC1FXeZ6rrmXXqU/6jvTA/m+QOmSP pYkarNV1HHvt0R/LdPLVJCmd4grSpOk3Uot0ZhyKenJ75eSBRxjn6/7dQjCLRJEMyEKP hUYv4IjDrD7h53FSR+NDCs7MZM/qtE1661UHzdRlmN8Lfj+uEz23aTsHc4mZv7zXpbji wquozkywd2mKLWXTdQ13D1LXgCD32/DzLwD05VuI16vuvO4IZ0E9BsFjWv76pHYlQxXK 7w== Received: from nasanppmta05.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3qbjwn9b7f-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 03 May 2023 17:34:44 +0000 Received: from nasanex01b.na.qualcomm.com (nasanex01b.na.qualcomm.com [10.46.141.250]) by NASANPPMTA05.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 343HYhNc024246 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 3 May 2023 17:34:43 GMT Received: from [10.71.110.193] (10.80.80.8) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Wed, 3 May 2023 10:34:43 -0700 Message-ID: Date: Wed, 3 May 2023 10:34:42 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.10.1 Subject: Re: [PATCH 2/4] drm/msm/dsi: Fix compressed word count calculation Content-Language: en-US To: Dmitry Baryshkov , Rob Clark , Abhinav Kumar , Sean Paul , David Airlie , Daniel Vetter , Marijn Suijten CC: Konrad Dybcio , , , , References: <20230405-add-dsc-support-v1-0-6bc6f03ae735@quicinc.com> <20230405-add-dsc-support-v1-2-6bc6f03ae735@quicinc.com> From: Jessica Zhang In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nasanex01b.na.qualcomm.com (10.46.141.250) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: hiUM3e70zqOygWXzuqNVxh0fZHx9FlJg X-Proofpoint-ORIG-GUID: hiUM3e70zqOygWXzuqNVxh0fZHx9FlJg X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-05-03_12,2023-05-03_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 malwarescore=0 impostorscore=0 phishscore=0 suspectscore=0 adultscore=0 mlxlogscore=999 lowpriorityscore=0 priorityscore=1501 clxscore=1015 mlxscore=0 spamscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2303200000 definitions=main-2305030150 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/3/2023 1:26 AM, Dmitry Baryshkov wrote: > On 03/05/2023 04:19, Jessica Zhang wrote: >> Currently, word count is calculated using slice_count. This is incorrect >> as downstream uses slice per packet, which is different from >> slice_count. >> >> Slice count represents the number of soft slices per interface, and its >> value will not always match that of slice per packet. For example, it is >> possible to have cases where there are multiple soft slices per interface >> but the panel specifies only one slice per packet. >> >> Thus, use the default value of one slice per packet and remove >> slice_count >> from the word count calculation. >> >> Fixes: bc6b6ff8135c ("drm/msm/dsi: Use DSC slice(s) packet size to >> compute word count") >> Signed-off-by: Jessica Zhang >> --- >>   drivers/gpu/drm/msm/dsi/dsi_host.c | 9 ++++++++- >>   1 file changed, 8 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c >> b/drivers/gpu/drm/msm/dsi/dsi_host.c >> index 35c69dbe5f6f..b0d448ffb078 100644 >> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c >> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c >> @@ -996,7 +996,14 @@ static void dsi_timing_setup(struct msm_dsi_host >> *msm_host, bool is_bonded_dsi) >>           if (!msm_host->dsc) >>               wc = hdisplay * dsi_get_bpp(msm_host->format) / 8 + 1; >>           else >> -            wc = msm_host->dsc->slice_chunk_size * >> msm_host->dsc->slice_count + 1; >> +            /* >> +             * When DSC is enabled, WC = slice_chunk_size * >> slice_per_packet + 1. >> +             * Currently, the driver only supports default value of >> slice_per_packet = 1 >> +             * >> +             * TODO: Expand drm_panel struct to hold slice_per_packet >> info >> +             *       and adjust DSC math to account for >> slice_per_packet. > > slice_per_packet is not a part of the standard DSC, so I'm not sure how > that can be implemented. And definitely we should not care about the > drm_panel here. It should be either a part of drm_dsc_config, or > mipi_dsi_device. Hi Dmitry, IIRC slice per packet is given by the panel specs with the default value being 1 if no value is specified, so it might be better to have it as part of mipi_dsi_device. Will update the TODO comment accordingly. Thanks, Jessica Zhang > >> +             */ >> +            wc = msm_host->dsc->slice_chunk_size + 1; >>           dsi_write(msm_host, REG_DSI_CMD_MDP_STREAM0_CTRL, >>               DSI_CMD_MDP_STREAM0_CTRL_WORD_COUNT(wc) | >> > > -- > With best wishes > Dmitry >