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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12155C433EF for ; Mon, 4 Oct 2021 09:37:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E635F610A8 for ; Mon, 4 Oct 2021 09:37:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231932AbhJDJjZ (ORCPT ); Mon, 4 Oct 2021 05:39:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37906 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232305AbhJDJjY (ORCPT ); Mon, 4 Oct 2021 05:39:24 -0400 Received: from lb1-smtp-cloud7.xs4all.net (lb1-smtp-cloud7.xs4all.net [IPv6:2001:888:0:108::1a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7D0A2C061745; Mon, 4 Oct 2021 02:37:31 -0700 (PDT) Received: from cust-b5b5937f ([IPv6:fc0c:c16d:66b8:757f:c639:739b:9d66:799d]) by smtp-cloud7.xs4all.net with ESMTPA id XKPVmnnng3tiGXKPZmgzkA; Mon, 04 Oct 2021 11:37:29 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xs4all.nl; s=s2; t=1633340249; bh=5Ci8s2DazLaZ9bxmkGNuyIZQ7JnbHSU01SAmc2+SYf8=; h=Subject:To:From:Message-ID:Date:MIME-Version:Content-Type:From: Subject; b=hxnXeA36b/YS5wIwszTrjo0on9Mh/kY18flFMAroeH0pWIBptM2ZuAHrMfh/ukWvo ZAuepwZGCPD0GZ5jmc1jTokS4lUgWIOlG4rqvYcStPV5L6Qr2021UwcphluhCJ4dUI q5kHY4JhWG3Sb2EUwqxFO2FXKqrFcntkA5ntHjhzzT5s7brFeb1WAiMQVS8PpR2+XH d+Nkt1UY14H9Dp2ufZoKEj0TO3CzxfGzFTiqVys5lPv9oA3AsKqfSeAs4r4dXF6CAy j1Ucao+6x302d0QoZ2hFNdMoPRnYUBWtOjFpYCaLHk1d/UmlBsRMbgB/iO7DNK8wFL rIvqnefJtY3Wg== Subject: Re: [PATCH v4] media: mtk-vpu: Ensure alignment of 8 for DTCM buffer To: Dafna Hirschfeld , linux-media@vger.kernel.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org Cc: Alexandre Courbot , kernel@collabora.com, Enric Balletbo i Serra , dafna3@gmail.com, tiffany.lin@mediatek.com, andrew-ct.chen@mediatek.com, minghsiu.tsai@mediatek.com, houlong.wei@mediatek.com, mchehab@kernel.org, matthias.bgg@gmail.com References: <20210920170408.1561-1-dafna.hirschfeld@collabora.com> From: Hans Verkuil Message-ID: Date: Mon, 4 Oct 2021 11:37:25 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: <20210920170408.1561-1-dafna.hirschfeld@collabora.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4xfBcoqINj/QBOZ/cBR0T0r4mV2UCZeOAv+LCbTi5subfRNdA0TIAV5vIjv8LEPzZsM7FJ2HPeqXl8QUUHI2fYAjML5dhqX0Zl29qOe6C1CVPgRSBqJr8Q t9E5Nit1WcGBgxnv+FVRiWysil7iyaSHSmIR+QlmErwseMha6D7Z6pHVzAwjBsbqICzsKlUiurPIXW/Y5QV21Uir0IVucKS//1W95OxRiplt2NmMEDRV2ROi x5YSk7d66zaqovSFB+FqC8kh8RX5siBP+Vv2wJ2dex/wb2TIx/EtsZjdPVlGImmb1p+FQOUtAci0ryGujSnCvkTxDz6lYLQjgYr5sWjW9WQP1p221jDkBATe J551v1a6DqFucU5c7w3gd+F+AlliJs71K04GO5AkqKMg77MV+S3TcFI//5cYKOBRQAeTEaiS6IjNCdC+0wwEpseNkT9XRbop7b/72wEunMkGGwEgY/ZIXe9j yniV/33nB/CdACdZEPcIWHdE04HqXqtLAFXfhxX0/NkNJgB006kA+K6WHcYQt+lIlRSWziUDoXRMQjh6pxx0zM2m8w9d44l2HD+1FfCk/cpt076m1IIaSpvU /jK8cP/lkXsNYCXAAct5XYR+F37O8WCUgym82j+rC9BYoX5ntp0DxNA5qRMZbD4Hs4b3ZWQzdQJlfk/LcNPDXyfSTIV0a2+7z+JJxVcsaAbvBw== Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On 20/09/2021 19:04, Dafna Hirschfeld wrote: > From: Alexandre Courbot > > When running memcpy_toio: > memcpy_toio(send_obj->share_buf, buf, len); > it was found that errors appear if len is not a multiple of 8: > > [58.350841] mtk-mdp 14001000.rdma: processing failed: -22 Why do errors appear? Is that due to a HW bug? Some other reason? > > This patch ensures the copy of a multiple of 8 size by calling > round_up(len, 8) when copying > > Fixes: e6599adfad30 ("media: mtk-vpu: avoid unaligned access to DTCM buffer.") > Signed-off-by: Alexandre Courbot > Signed-off-by: Enric Balletbo i Serra > Signed-off-by: Dafna Hirschfeld > Reviewed-by: Houlong Wei > --- > changes since v3: > 1. multile -> multiple > 2. add inline doc > > changes since v2: > 1. do the extra copy only if len is not multiple of 8 > > changes since v1: > 1. change sign-off-by tags > 2. change values to memset > > drivers/media/platform/mtk-vpu/mtk_vpu.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/platform/mtk-vpu/mtk_vpu.c b/drivers/media/platform/mtk-vpu/mtk_vpu.c > index ec290dde59cf..1df031716c8f 100644 > --- a/drivers/media/platform/mtk-vpu/mtk_vpu.c > +++ b/drivers/media/platform/mtk-vpu/mtk_vpu.c > @@ -349,7 +349,20 @@ int vpu_ipi_send(struct platform_device *pdev, > } > } while (vpu_cfg_readl(vpu, HOST_TO_VPU)); > > - memcpy_toio(send_obj->share_buf, buf, len); > + /* > + * when copying data to the vpu hardware, the memcpy_toio operation must copy > + * a multiple of 8. Otherwise the processing fails Same here: it needs to explain why the processing fails. > + */ > + if (len % 8 != 0) { > + unsigned char data[SHARE_BUF_SIZE]; Wouldn't it be more robust if you say: unsigned char data[sizeof(send_obj->share_buf)]; I also think that the SHARE_BUF_SIZE define needs a comment stating that it must be a multiple of 8, otherwise unexpected things can happen. You also noticed that the current SHARE_BUF_SIZE define is too low, but I saw no patch correcting this. Shouldn't that be fixed as well? Regards, Hans > + > + memset(data + len, 0, sizeof(data) - len); > + memcpy(data, buf, len); > + memcpy_toio(send_obj->share_buf, data, round_up(len, 8)); > + } else { > + memcpy_toio(send_obj->share_buf, buf, len); > + } > + > writel(len, &send_obj->len); > writel(id, &send_obj->id); > >