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 EF255C4332F for ; Fri, 11 Mar 2022 15:46:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348744AbiCKPrK (ORCPT ); Fri, 11 Mar 2022 10:47:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47322 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348795AbiCKPrD (ORCPT ); Fri, 11 Mar 2022 10:47:03 -0500 Received: from mail-lj1-x232.google.com (mail-lj1-x232.google.com [IPv6:2a00:1450:4864:20::232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1564F1C6656 for ; Fri, 11 Mar 2022 07:45:59 -0800 (PST) Received: by mail-lj1-x232.google.com with SMTP id u7so12495158ljk.13 for ; Fri, 11 Mar 2022 07:45:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=10XF3Sb+t0GCaPOcQ9XoyXqUIC9CjyYdWscRYcObAxw=; b=MqSyuOe34h+f5EWwR/oM3slrJ38qINF04yiqUGK9i44Eg7rBVyesJHW1EnFC5kq8Fz lk+2YfR6+b43HpQckMotOid77fcXOQCYnCzxj1VBwif0v7RCPtuA/XLZTOUL3TGLQ5aP rQQEfHcA3U6Ckvf/b/iG+3oXnpYqaTOumz8wAkXkJ28WbzSqpcBZIFq8ncUer5twWgks FOJuSVG0lF2of7EiLc6kYvyyb0pg3ayR7my6BVOGNSBBms3Z+ikWZdLDJdqgvWdJqhJe L4QlwgEkOq4Qz46/Q/RRjPefsiQTSwFPLy5q6vZRgKOnqEz3+Npwf2GWlZojgDZgRcgm baow== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=10XF3Sb+t0GCaPOcQ9XoyXqUIC9CjyYdWscRYcObAxw=; b=5GS6T+ai3QqN/PO7Phf4UhK9V5e2lBKMRZDRm9+15E383s8mTX7x0dYDLQea1K3tzY /u5MdbV4cYyWdBEvtEKy82pMvyvpBogRe0x1f5x197VH4BPRU3LPY+cA1hHsR4CUB5uH D0Bv/PhdeXXaOgCLnbGNL52Z9MPO5YTc15yR0lFu1wFRwo2fkypEZ60mx7C9IFVdKVj7 dpRkanjN6Qm/WcafGPwZCb5V7M8I38vJZnK5R1LGK/WIQ3dG/qCrXQ1zGM3iPgoUs35C fHRsMTPVP2bP2hl+tIvj3kHbYMOvbKMfk3UrBuwGshyj2oA0Kvm4YLT/EcQEssY0ajgs yZaw== X-Gm-Message-State: AOAM533OThM9m/TcyWE4fRZSy9Gkyjjvw6p+vlJbZVgTn0u1vumTif1O e8KVvR20zyENRmwEry7OK3MQmHY+Bz8GG5wA76QfbA== X-Google-Smtp-Source: ABdhPJyKLXL/cjixS70H+wB5WRjtfcEBo2CKEa89VicVYZWBqrQ7uCDzqe5Ilvrer3zvBAGc4wkBHELro4zTjGulY/w= X-Received: by 2002:a2e:8603:0:b0:246:24c:b79c with SMTP id a3-20020a2e8603000000b00246024cb79cmr6543962lji.367.1647013557376; Fri, 11 Mar 2022 07:45:57 -0800 (PST) MIME-Version: 1.0 References: <20220304135134.47827-1-yann.gautier@foss.st.com> <20220304135134.47827-2-yann.gautier@foss.st.com> In-Reply-To: From: Ulf Hansson Date: Fri, 11 Mar 2022 16:45:21 +0100 Message-ID: Subject: Re: [PATCH 1/3] dt-bindings: mmc: mmci: add a property to disable DMA LLI To: Yann Gautier Cc: Rob Herring , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, Alexandre Torgue , Christophe Kerello , Linus Walleij , Ludovic Barre , Maxime Coquelin , Philipp Zabel , Russell King , Marek Vasut , kernel@dh-electronics.com, Manivannan Sadhasivam , Grzegorz Szymaszek Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 10 Mar 2022 at 17:00, Yann Gautier wrote: > > On 3/8/22 11:57, Ulf Hansson wrote: > > Hi Yann, > > > > On Fri, 4 Mar 2022 at 14:52, Yann Gautier wrote: > >> > >> On STMicroelectronics variant of PL18x, the DMA Linked Lists are supported > >> starting from revision v2 of the peripheral. But it has limitations, > >> as all the buffers should be aligned on block size (except the last one). > >> But this cannot be guaranteed with SDIO. We should then have a property > >> to disable the support of LLI. > > > > Indeed, the buffer handling with SDIO is somewhat special, which also > > has been discussed several times on LKML before. In principle, we need > > the SDIO func drivers to respect buffer limitations that should be > > specified by the mmc host drivers. Quite similar to what we already > > have for block devices, like ->max_seg_size, ->max_seg, etc, that is > > set per mmc host. > > > > I realize that implementing something like the above requires bigger > > changes, which is why mmc host drivers instead validates the sglists > > and the elements. In some cases that means returning an error code and > > in others it could mean falling back to a non-DMA based I/O mode. > > > > For the stm32_sdmmc variant, it looks like the sglist validation is > > being managed in sdmmc_idma_validate_data() already. Can it be > > extended to cover this case too, rather than using a DT property? > > > > Kind regards > > Uffe > > Hi Ulf, > > OK, I'll check what can be done for this. Patches 1 and 2 can be > dropped, they will be reworked. Okay. > But patch 3 of this series could be taken, as not linked to LLI > management. Should I push it again alone, or could you review it directly? I have some comments/questions on it, but perhaps it makes it easier for people to follow the discussion if it is done separately. So please push it alone, then I will review it. [...] Kind regards Uffe