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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D1CEC10DCE for ; Tue, 10 Mar 2020 23:09:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 523FB222C3 for ; Tue, 10 Mar 2020 23:09:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=walle.cc header.i=@walle.cc header.b="EBaUbOvI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727736AbgCJXJy (ORCPT ); Tue, 10 Mar 2020 19:09:54 -0400 Received: from ssl.serverraum.org ([176.9.125.105]:46611 "EHLO ssl.serverraum.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726325AbgCJXJx (ORCPT ); Tue, 10 Mar 2020 19:09:53 -0400 Received: from apollo.fritz.box (unknown [IPv6:2a02:810c:c200:2e91:6257:18ff:fec4:ca34]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id 88EFD23E76; Wed, 11 Mar 2020 00:09:49 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1583881790; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=LdXbv3uElz5yQ5qGjxhsqm0U2lY05oTqfEXnfYIHMz8=; b=EBaUbOvIfKodPUEguZcuPIKEw1o7IPARUaZHCLEDdGGbzV9pgOXIcrsnTPxVyxkKVTzMWm zSIkvieCuDuHiLrqpx9fzACg5r+sdU/+e4nK8SMjKvhpl/Qe1MIz4orUWaigbbrfr6awsY hDK7YzdcBVlmOyFODj7Rzf356IOjA/A= From: Michael Walle To: linux-kernel@vger.kernel.org Cc: Lee Jones , Michael Walle , Christoph Hellwig , Rob Herring , Robin Murphy , Russell King Subject: [RFC PATCH] mfd: mfd-core: inherit only valid dma_masks/flags from parent Date: Wed, 11 Mar 2020 00:09:35 +0100 Message-Id: <20200310230935.23962-1-michael@walle.cc> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spamd-Bar: ++++ X-Rspamd-Server: web X-Rspamd-Queue-Id: 88EFD23E76 X-Spamd-Result: default: False [4.90 / 15.00]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; R_MISSING_CHARSET(2.50)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MIME_GOOD(-0.10)[text/plain]; NEURAL_SPAM(0.00)[0.530]; BROKEN_CONTENT_TYPE(1.50)[]; DKIM_SIGNED(0.00)[]; RCPT_COUNT_SEVEN(0.00)[7]; MID_CONTAINS_FROM(1.00)[]; RCVD_COUNT_ZERO(0.00)[0]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:31334, ipnet:2a02:810c:8000::/33, country:DE] Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Only copy the dma_masks and flags from the parent device, if the parent has a valid dma_mask/flags. Commit cdfee5623290 ("driver core: initialize a default DMA mask for platform device") initialize the DMA masks of a platform device. But if the parent doesn't have a dma_mask set, for example if it's an I2C device, the dma_mask of the child platform device will be set to zero again. Which leads to many "DMA mask not set" warnings, if the MFD cell has the of_compatible property set. [ 1.877937] sl28cpld-pwm sl28cpld-pwm: DMA mask not set [ 1.883282] sl28cpld-pwm sl28cpld-pwm.0: DMA mask not set [ 1.888795] sl28cpld-gpio sl28cpld-gpio: DMA mask not set Thus a MFD child should just inherit valid dma_masks and keep the platform default otherwise. Cc: Christoph Hellwig Cc: Rob Herring Cc: Robin Murphy Cc: Russell King Signed-off-by: Michael Walle --- Hi, I don't know if that is the correct way of handling things. Maybe I'm also doing something wrong in my driver, I had a look at other I2C MFD drivers but couldn't find a clue why they shouldn't have the same problem. There was also a thread [1] about this topic, but there seems to be no conclusion. [1] https://www.spinics.net/lists/linux-renesas-soc/msg31581.html drivers/mfd/mfd-core.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index b9eb8f40c073..5d8ea5e8e93c 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -139,9 +139,12 @@ static int mfd_add_device(struct device *parent, int id, pdev->dev.parent = parent; pdev->dev.type = &mfd_dev_type; - pdev->dev.dma_mask = parent->dma_mask; - pdev->dev.dma_parms = parent->dma_parms; - pdev->dev.coherent_dma_mask = parent->coherent_dma_mask; + if (parent->dma_mask) + pdev->dev.dma_mask = parent->dma_mask; + if (parent->dma_parms) + pdev->dev.dma_parms = parent->dma_parms; + if (parent->coherent_dma_mask) + pdev->dev.coherent_dma_mask = parent->coherent_dma_mask; ret = regulator_bulk_register_supply_alias( &pdev->dev, cell->parent_supplies, -- 2.20.1