From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f177.google.com (mail-pf1-f177.google.com [209.85.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 857972C9E for ; Fri, 7 Jan 2022 09:35:17 +0000 (UTC) Received: by mail-pf1-f177.google.com with SMTP id b22so4749283pfb.5 for ; Fri, 07 Jan 2022 01:35:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=fjiy0XooAZ6+kW7wDLSv0ZRGyBQbrxYjLs1RiRmdLbE=; b=QvJo4nFH0gD8APv38byE5spLLGm2EstyxyTk2J3FFBpW7w7wx3d58C4oK9BSis/uWT V1neR7ko1JCTXSYbOsosrDSHBLVmVjSezPdgElFoRM5iWaBNNSSD5HqnNWw1baqQnlWR Dfu9ZPxAq50562bbUX1Ev9gRjkuCgBJ5lrK+o= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=fjiy0XooAZ6+kW7wDLSv0ZRGyBQbrxYjLs1RiRmdLbE=; b=V8tEDXS4BpVc7G6Lo9atKp8j3W+4KCRN+51CSltOLxAgBP4H9atgAnrdEAw+1yx+o9 45bS2jg5YQQEl/VBYTCu0NCHfpW2A4vFJkCEm8HoUD0GgrKYzqGwGAR33P2Nsi/o2/0d nN91643ECRgYf8fQ08L4DJwEDReifqbFvCjlhXFMC/HKT0Z4BNr0s9XKolN1Q+HzyjxE SNy+J4Y6qVWQhAEKQR5zIp9wtwaUKXNZlkHhpobASNGmwqzmnJm187EhRm8lgZBZg1hZ AJuRYdaue/fJtY+hA/L/4WsNN07Sg2JVX2mA/TFrnYRdgvx81JypFdCnQSCCQjSP2qvq cmoQ== X-Gm-Message-State: AOAM531pYWCv/41LWneVA1c/eSaheBv01dFmWwzqvuJaxI9tCoN7v/EM 3rnKxM9ksu28ib41Sr2pAR3qAQ== X-Google-Smtp-Source: ABdhPJwXKfTmxMvstQkseMraIWF9HRswARtFjx8amtQ1SIu1hk1yMo3q40/yRoCkMDPgQvU/zWmg0Q== X-Received: by 2002:a05:6a00:1a4f:b0:4bb:113a:677c with SMTP id h15-20020a056a001a4f00b004bb113a677cmr63742556pfv.63.1641548117149; Fri, 07 Jan 2022 01:35:17 -0800 (PST) Received: from wenstp920.tpe.corp.google.com ([2401:fa00:1:10:8f6b:ee:64d8:ae81]) by smtp.gmail.com with ESMTPSA id j17sm5269192pfu.77.2022.01.07.01.35.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Jan 2022 01:35:16 -0800 (PST) From: Chen-Yu Tsai To: Ezequiel Garcia , Philipp Zabel , Mauro Carvalho Chehab , Hans Verkuil , Greg Kroah-Hartman Cc: Chen-Yu Tsai , linux-media@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH RFT v2 5/8] media: hantro: jpeg: Add COM segment to JPEG header to align image scan Date: Fri, 7 Jan 2022 17:34:52 +0800 Message-Id: <20220107093455.73766-6-wenst@chromium.org> X-Mailer: git-send-email 2.34.1.575.g55b058a8bb-goog In-Reply-To: <20220107093455.73766-1-wenst@chromium.org> References: <20220107093455.73766-1-wenst@chromium.org> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The JPEG header size is not 64-bit aligned. This makes the driver require a bounce buffer for the encoded JPEG image scan output. Add a COM (comment) segment to the JPEG header so that the header size is a multiple of 64 bits. This will then allow dropping the use of the bounce buffer, and instead have the hardware write out to the capture buffer directly. Signed-off-by: Chen-Yu Tsai --- drivers/staging/media/hantro/hantro_jpeg.c | 23 +++++++++++++++++++++- drivers/staging/media/hantro/hantro_jpeg.h | 2 +- 2 files changed, 23 insertions(+), 2 deletions(-) diff --git a/drivers/staging/media/hantro/hantro_jpeg.c b/drivers/staging/media/hantro/hantro_jpeg.c index 7d4018bd6876..e63eeef3952d 100644 --- a/drivers/staging/media/hantro/hantro_jpeg.c +++ b/drivers/staging/media/hantro/hantro_jpeg.c @@ -6,6 +6,9 @@ * Copyright (C) Jean-Francois Moine (http://moinejf.free.fr) * Copyright (C) 2014 Philipp Zabel, Pengutronix */ + +#include +#include #include #include #include @@ -140,7 +143,7 @@ static const unsigned char chroma_ac_table[] = { * and we'll use fixed offsets to change the width, height * quantization tables, etc. */ -static const unsigned char hantro_jpeg_header[JPEG_HEADER_SIZE] = { +static const unsigned char hantro_jpeg_header[] = { /* SOI */ 0xff, 0xd8, @@ -247,11 +250,29 @@ static const unsigned char hantro_jpeg_header[JPEG_HEADER_SIZE] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + /* COM */ + 0xff, 0xfe, 0x00, 0x03, 0x00, + /* SOS */ 0xff, 0xda, 0x00, 0x0c, 0x03, 0x01, 0x00, 0x02, 0x11, 0x03, 0x11, 0x00, 0x3f, 0x00, }; +/* + * JPEG_HEADER_SIZE is used in other parts of the driver in lieu of + * "sizeof(hantro_jpeg_header)". The two must be equal. + */ +static_assert(sizeof(hantro_jpeg_header) == JPEG_HEADER_SIZE); + +/* + * hantro_jpeg_header is padded with a COM segment, so that the payload + * of the SOS segment (the entropy-encoded image scan), which should + * trail the whole header, is 8-byte aligned for the hardware to write + * to directly. + */ +static_assert(IS_ALIGNED(sizeof(hantro_jpeg_header), 8), + "Hantro JPEG header size needs to be 8-byte aligned."); + static unsigned char jpeg_scale_qp(const unsigned char qp, int scale) { unsigned int temp; diff --git a/drivers/staging/media/hantro/hantro_jpeg.h b/drivers/staging/media/hantro/hantro_jpeg.h index f33c492134e4..0b49d0b82caa 100644 --- a/drivers/staging/media/hantro/hantro_jpeg.h +++ b/drivers/staging/media/hantro/hantro_jpeg.h @@ -1,6 +1,6 @@ /* SPDX-License-Identifier: GPL-2.0+ */ -#define JPEG_HEADER_SIZE 619 +#define JPEG_HEADER_SIZE 624 #define JPEG_QUANT_SIZE 64 struct hantro_jpeg_ctx { -- 2.34.1.575.g55b058a8bb-goog