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dmarc=fail (p=none dis=none) header.from=collabora.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:Cc:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=om1Wbpwi4IiT77c0hfvDqpwIJeeTFTVx5ZXo9APV9GI=; b=Dz+9Lp5jVwaJYV4r/X+jCjdRvT lFXwsvK+k2kLUxU5tgGOAgjhyDPYjczFpflp3OdcoxNr5XjQDx2+4FfAD1K7u8qsmy3BvODvdr3XW kEqVn20qvn05H/kZRTOXwFc026FpvWzwg4LMXx5kj2IhuJtJntdvV50il/DcOYbqlTyQOrA65+/qQ hpK8dG3mySb0cpW2tr+NJAhPE3CiIAD0fio2lZvaWFMDN3ufTnSv8F8w556jcuNiWOcJSxCS5NAvc 7fu+f27IbXBBQ53YjS7Ga40P7k9JXNARrPtPg1XK5RmDsE8NrZdCqWrX91LFdkbaxQVpT3+LlrT0b +nFVOHRw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mSL4r-002BYu-Pf; Mon, 20 Sep 2021 15:19:29 +0000 Received: from bhuna.collabora.co.uk ([2a00:1098:0:82:1000:25:2eeb:e3e3]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mSL4o-002BXn-4f for linux-mediatek@lists.infradead.org; Mon, 20 Sep 2021 15:19:27 +0000 Received: from [IPv6:2a02:810a:880:f54:34ca:272f:b5af:bab9] (unknown [IPv6:2a02:810a:880:f54:34ca:272f:b5af:bab9]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: dafna) by bhuna.collabora.co.uk (Postfix) with ESMTPSA id D30571F42F71; Mon, 20 Sep 2021 16:19:21 +0100 (BST) Subject: Re: [PATCH v3] media: mtk-vpu: Ensure alignment of 8 for DTCM buffer To: Hans Verkuil , 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, mchehab@kernel.org, tfiga@chromium.org, minghsiu.tsai@mediatek.com, houlong.wei@mediatek.com, andrew-ct.chen@mediatek.com, tiffany.lin@mediatek.com, matthias.bgg@gmail.com, courbot@chromium.org, hsinyi@chromium.org, eizan@chromium.org References: <20210825101717.18075-1-dafna.hirschfeld@collabora.com> From: Dafna Hirschfeld Message-ID: <8c8336ff-57aa-dac8-d4ef-5d1dd120b2db@collabora.com> Date: Mon, 20 Sep 2021 17:19:19 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210920_081926_344090_9D2AB224 X-CRM114-Status: GOOD ( 29.98 ) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On 01.09.21 10:50, Hans Verkuil wrote: > On 25/08/2021 12:17, 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 >> >> This patch ensures the copy of a multile of 8 size by calling > > multile -> multiple > >> 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 >> --- >> 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 | 11 ++++++++++- >> 1 file changed, 10 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..658161ee3e4e 100644 >> --- a/drivers/media/platform/mtk-vpu/mtk_vpu.c >> +++ b/drivers/media/platform/mtk-vpu/mtk_vpu.c >> @@ -349,7 +349,16 @@ int vpu_ipi_send(struct platform_device *pdev, >> } >> } while (vpu_cfg_readl(vpu, HOST_TO_VPU)); >> >> - memcpy_toio(send_obj->share_buf, buf, len); >> + if (len % 8 != 0) { > > You need to add a comment here explaining why this is done (basically what > you also say in the commit log). > > Otherwise people would have to dig into the git log to figure out why this > code is the way it is. > > Is len often not a multiple of 8? If that's the case, then it might be easier > to just always do the memset/memcpy. I wrote a program that prints the sizes of all possible messages: http://ix.io/3zsr compiling it to arm64 gives: sizeof(mdp_ipi_comm) is 24 sizeof(mdp_ipi_init) is 16 sizeof(venc_ap_ipi_msg_deinit) is 8 sizeof(venc_ap_ipi_msg_enc_ext) is 164 sizeof(venc_ap_ipi_msg_enc) is 32 sizeof(venc_ap_ipi_msg_set_param_ext) is 144 sizeof(venc_ap_ipi_msg_set_param) is 48 sizeof(venc_ap_ipi_msg_init) is 16 sizeof(vdec_ap_ipi_cmd) is 8 sizeof(vdec_ap_ipi_init) is 16 sizeof(vdec_ap_ipi_dec_start) is 24 BUT, when printing the size in the kernel I got "sizeof(mdp_ipi_comm) = 20" and found out that this is due to the macro #pragma pack(push, 4) in mtk_mdp_ipi.h so for mdp it makes sens to always do the memset/memcpy but for mtk-vcodec it is not necessary. In addition, if the message is one of 'venc_ap_ipi_msg_enc_ext' or 'venc_ap_ipi_msg_set_param_ext' then vpu_ipi_send will fail in the beginning of the function since in those cases we have 'len > sizeof(send_obj->share_buf)'. so I should send a patch that set SHARE_BUF_SIZE to e.g. 200 I also found out that adding #pragma pack(push, 4) to the definitions of the mtk-vcodec messages has no influence but maybe this should be added since we copy those messages to hw , so might avoid future bugs. thanks, Dafna > > Regards, > > Hans > >> + unsigned char data[SHARE_BUF_SIZE]; >> + >> + 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); >> >> > _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek