From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933505AbcIEPjz (ORCPT ); Mon, 5 Sep 2016 11:39:55 -0400 Received: from mout.kundenserver.de ([212.227.126.187]:54583 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932557AbcIEPjx (ORCPT ); Mon, 5 Sep 2016 11:39:53 -0400 From: Arnd Bergmann To: Leo Li Cc: Felipe Balbi , Russell King - ARM Linux , Grygorii Strashko , Catalin Marinas , Yoshihiro Shimoda , "linux-usb@vger.kernel.org" , Sekhar Nori , lkml , David Fisher , "Thang Q. Nguyen" , Alan Stern , Greg Kroah-Hartman , "linux-arm-kernel@lists.infradead.org" , Stuart Yoder , Scott Wood Subject: Re: [PATCH] usb: dwc3: host: inherit dma configuration from parent dev Date: Mon, 05 Sep 2016 17:39:27 +0200 Message-ID: <4865343.bOXkeC8XtQ@wuerfel> User-Agent: KMail/5.1.3 (Linux/4.4.0-34-generic; KDE/5.18.0; x86_64; ; ) In-Reply-To: References: <6414695.LEIYfGPUEg@wuerfel> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:IVj+D1+jkAZPlaOAAbAEATIzUUVOIOKjflkp8jvW/NDmXgzy4kJ FTi3JwUQQqvowUeZHG7NG+KAn2oIqUWs31fz79shCBZJrJzuXT1hAc28BTOpH7zKQq1SarX aKr/bVlZ1ylLeykk8azI052OHKpWlSXWVHkg4mUO713R9Pl+h4k0eBnJVha40DoctE7eNEk +/5D+ptCM8VQriov0eHRg== X-UI-Out-Filterresults: notjunk:1;V01:K0:/Z4pKZlhtuI=:x0b6NktMssRLJvAFIFSkqb CBUssKlGtmMSeiiaDBHaZQGBPSv20SSval9z03H3/Lf+mAnC9DUJGcJ+AOJS1T3bEI3/IS87R UlKHyi1+1C+342gjNon703tiQSsYmiIygE7Lg2/KxcC/sDTXk/eZLFQROdfsQaIQ8w3cuvd1C /E4/klys1IT2OOaP/mSlV1ZcXgwRQTUPGQaPrQemRSDIWD50hpfCBBB9dzIbsUIuqkifME5Wq 7KC1UIGoHsJXvsAduGwPBWIULUme2kMviiWiG2Ip8OOYHDJc0IVahQfKyNTjPj5nL8j4Fr8Ef S2mBMpoC+yzG8otH8B4L8Jdgu8jixQKFM06+ATh3r9WovquPIGNtx3G099gzYvLRE2bcbkHqL PoTjf2O6r3zqzyvxXKcp4cR2LdzhTqx6meSQ6HH5GE65KvvSY/y94W1vG1ynBeKHBNoV+h/nJ Nr1XyH4QE9mdCgqJ9x6rkIhvduPutONqsRgGxJJ6KArvum4Fkew1YQGgV7kXcFUNUN1YBSVCS rFgsDS6ab1Lpl+xuX5PTH/t5cbU/aYMlhZtsvSGYVjQlxqZMaNKK1SX5MOtMQp/uEiuaEv+jL mZz+Im+w/li6yILzeaEdhiK8IbzQJWbGZH6Pj/vDj2S9CioJyT9bDZzF04unajzoOtueK+O/U W1BAz34JVrQiQK1RiBzm52YeTs/FXndW2CkwflKNBMnu9vzjcIm9fXtD81Wpiq0+Dm9n/HT7C +I+TV+0UWVGdgDIF Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Friday, September 2, 2016 5:16:31 PM CEST Leo Li wrote: > > Can we use the firmware or bootloader information to provide the > default dma-mapping attributes for devices that doesn't have an > of_node pointer or ACPI data? This will at least restore what we had > previously provided . I'm concerned that changing all the drivers > that are creating child device will be a big effort. Like I mentioned > in another thread, there are many instances of platform_device_add() > under the drivers/ directory. Fortunately, there are not too many drivers that call platform_device_add *and* try to set up a dma mask for the child device: git grep -wl dma_mask drivers | xargs grep -wl 'platform_device_\(add\|register\)' drivers/base/platform.c drivers/bcma/main.c drivers/eisa/virtual_root.c drivers/mfd/mfd-core.c drivers/mfd/omap-usb-host.c drivers/misc/mic/card/mic_x100.c drivers/platform/goldfish/pdev_bus.c drivers/ssb/main.c drivers/usb/chipidea/core.c drivers/usb/dwc3/dwc3-exynos.c drivers/usb/dwc3/host.c drivers/usb/gadget/udc/bdc/bdc_pci.c drivers/usb/host/bcma-hcd.c drivers/usb/host/fsl-mph-dr-of.c drivers/usb/host/ssb-hcd.c drivers/usb/misc/ftdi-elan.c drivers/usb/musb/blackfin.c drivers/usb/musb/musb_dsps.c drivers/usb/musb/omap2430.c drivers/usb/musb/ux500.c Most of these are probably never used with any nonstandard DMA settings (IOMMU, cache coherency, offset, ...). One thing we could possibly do is to go through these and replace the hardcoded dma mask setup with of_dma_configure() in all cases in which we actually use DT for probing, which should cover the interesting cases. Arnd