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 16484C4332F for ; Fri, 7 Jan 2022 09:35:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236936AbiAGJfM (ORCPT ); Fri, 7 Jan 2022 04:35:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236763AbiAGJfJ (ORCPT ); Fri, 7 Jan 2022 04:35:09 -0500 Received: from mail-pl1-x62a.google.com (mail-pl1-x62a.google.com [IPv6:2607:f8b0:4864:20::62a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D86EC061201 for ; Fri, 7 Jan 2022 01:35:08 -0800 (PST) Received: by mail-pl1-x62a.google.com with SMTP id s15so4454041plg.12 for ; Fri, 07 Jan 2022 01:35:08 -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=rdOIoZ+TgGuU5AsegB3fHTze1qyXqLuPOXXXHf1uigo=; b=N/iRPyGDvOpeNg78lIyT9dxhuh54SZrC9Wq054ryPDJeYxTiaD/9ob0UvN0CKHuB5/ VEWXt30685YBAH/gbvqXGQQlacbvGPse47ag/5OQtn126Yuo8qqqjdl/QpBVtQ3I6yxt YAmHBVVZepadD41/3AdToNEZP/ml4Xe0uQ34A= 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=rdOIoZ+TgGuU5AsegB3fHTze1qyXqLuPOXXXHf1uigo=; b=r415IMwYaUh7XoHIoh7lkhYc+wlmUMu5R1UAUlr11Bu2Ivsyqk3b4GafAUcZZbaarL y4gIcUuHW+w1Z7KzLeBZ0YwA5s53rmHzXkc/1cplmaR6ChzljRkJgD/5FH4sL3e6JGCl WP3MbAV8Fq/LyNuRoOc97tRa5o7AcyCeDbrGhCJfSr55BRDDmvnA2cF2glYxrA1XYZrt UHqnCA16zCyTyXKZi6ke1Z8VqK5c24UIAggXRjvMqo8oPrGeQ6K8qURT8gYQ3SgdOhXt fP8jKeQLkeGdc3hgjjyVS4cYXTZClnrywhU6rlqLBgO3NIoDz1WnPSyY6hefE2rJgmkf Q+7g== X-Gm-Message-State: AOAM5326q1OAUn0XHJ6J8sbosbPuTCiz7CuU6DXUu1gL+exeXLRWJSJk 9Pf1JzAQ8pprK0EDP0SLDB4InQ== X-Google-Smtp-Source: ABdhPJzWLTwfR71eotanrG4gal1FGzLpvAEjuqNZ8B7j935+/nKhzmavNQfJtAdv/Ldrgr775DlDYg== X-Received: by 2002:a17:902:dac7:b0:148:ea85:af4d with SMTP id q7-20020a170902dac700b00148ea85af4dmr62032775plx.131.1641548108204; Fri, 07 Jan 2022 01:35:08 -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.77.2022.01.07.01.35.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Jan 2022 01:35:07 -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 1/8] media: hantro: jpeg: Relax register writes before write starting hardware Date: Fri, 7 Jan 2022 17:34:48 +0800 Message-Id: <20220107093455.73766-2-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> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In the earlier submissions of the Hantro/Rockchip JPEG encoder driver, a wmb() was inserted before the final register write that starts the encoder. In v11, it was removed and the second-to-last register write was changed to a non-relaxed write, which has an implicit wmb() [1]. The rockchip_vpu2 (then rk3399_vpu) variant is even weirder as there is another writel_relaxed() following the non-relaxed one. Turns out only the last writel() needs to be non-relaxed. Device I/O mappings already guarantee strict ordering to the same endpoint, and the writel() triggering the hardware would force all writes to memory to be observed before the writel() to the hardware is observed. [1] https://lore.kernel.org/linux-media/CAAFQd5ArFG0hU6MgcyLd+_UOP3+T_U-aw2FXv6sE7fGqVCVGqw@mail.gmail.com/ Signed-off-by: Chen-Yu Tsai --- drivers/staging/media/hantro/hantro_h1_jpeg_enc.c | 3 +-- drivers/staging/media/hantro/rockchip_vpu2_hw_jpeg_enc.c | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/staging/media/hantro/hantro_h1_jpeg_enc.c b/drivers/staging/media/hantro/hantro_h1_jpeg_enc.c index 1450013d3685..03db1c3444f8 100644 --- a/drivers/staging/media/hantro/hantro_h1_jpeg_enc.c +++ b/drivers/staging/media/hantro/hantro_h1_jpeg_enc.c @@ -123,8 +123,7 @@ int hantro_h1_jpeg_enc_run(struct hantro_ctx *ctx) | H1_REG_AXI_CTRL_INPUT_SWAP32 | H1_REG_AXI_CTRL_OUTPUT_SWAP8 | H1_REG_AXI_CTRL_INPUT_SWAP8; - /* Make sure that all registers are written at this point. */ - vepu_write(vpu, reg, H1_REG_AXI_CTRL); + vepu_write_relaxed(vpu, reg, H1_REG_AXI_CTRL); reg = H1_REG_ENC_CTRL_WIDTH(MB_WIDTH(ctx->src_fmt.width)) | H1_REG_ENC_CTRL_HEIGHT(MB_HEIGHT(ctx->src_fmt.height)) diff --git a/drivers/staging/media/hantro/rockchip_vpu2_hw_jpeg_enc.c b/drivers/staging/media/hantro/rockchip_vpu2_hw_jpeg_enc.c index 4df16f59fb97..b931fc5fa1a9 100644 --- a/drivers/staging/media/hantro/rockchip_vpu2_hw_jpeg_enc.c +++ b/drivers/staging/media/hantro/rockchip_vpu2_hw_jpeg_enc.c @@ -152,8 +152,7 @@ int rockchip_vpu2_jpeg_enc_run(struct hantro_ctx *ctx) | VEPU_REG_INPUT_SWAP8 | VEPU_REG_INPUT_SWAP16 | VEPU_REG_INPUT_SWAP32; - /* Make sure that all registers are written at this point. */ - vepu_write(vpu, reg, VEPU_REG_DATA_ENDIAN); + vepu_write_relaxed(vpu, reg, VEPU_REG_DATA_ENDIAN); reg = VEPU_REG_AXI_CTRL_BURST_LEN(16); vepu_write_relaxed(vpu, reg, VEPU_REG_AXI_CTRL); -- 2.34.1.575.g55b058a8bb-goog