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=-7.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_PASS,USER_AGENT_MUTT 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 20AFDC04AB7 for ; Tue, 14 May 2019 18:39:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F299E20879 for ; Tue, 14 May 2019 18:39:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727618AbfENSjQ (ORCPT ); Tue, 14 May 2019 14:39:16 -0400 Received: from ste-pvt-msa1.bahnhof.se ([213.80.101.70]:63549 "EHLO ste-pvt-msa1.bahnhof.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726218AbfENSjQ (ORCPT ); Tue, 14 May 2019 14:39:16 -0400 X-Greylist: delayed 580 seconds by postgrey-1.27 at vger.kernel.org; Tue, 14 May 2019 14:39:15 EDT Received: from localhost (localhost [127.0.0.1]) by ste-pvt-msa1.bahnhof.se (Postfix) with ESMTP id D469A3F7F2; Tue, 14 May 2019 20:29:33 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at bahnhof.se Received: from ste-pvt-msa1.bahnhof.se ([127.0.0.1]) by localhost (ste-pvt-msa1.bahnhof.se [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ntDtz1TyoPSy; Tue, 14 May 2019 20:29:33 +0200 (CEST) Received: from localhost (h-41-252.A163.priv.bahnhof.se [46.59.41.252]) (Authenticated sender: mb547485) by ste-pvt-msa1.bahnhof.se (Postfix) with ESMTPA id 0C1D83F393; Tue, 14 May 2019 20:29:31 +0200 (CEST) Date: Tue, 14 May 2019 20:29:31 +0200 From: Fredrik Noring To: Robin Murphy Cc: laurentiu.tudor@nxp.com, hch@lst.de, stern@rowland.harvard.edu, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, marex@denx.de, JuergenUrban@gmx.de, leoyang.li@nxp.com, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v2 0/3] prerequisites for device reserved local mem rework Message-ID: <20190514182931.GA2559@sx9> References: <20190514143807.7745-1-laurentiu.tudor@nxp.com> <9d34015d-c219-179b-3141-4b0de3530ac3@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <9d34015d-c219-179b-3141-4b0de3530ac3@arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks Robin! > > For HCs that have local memory, replace the current DMA API usage > > with a genalloc generic allocator to manage the mappings for these > > devices. > > This is in preparation for dropping the existing "coherent" dma > > mem declaration APIs. Current implementation was relying on a short > > circuit in the DMA API that in the end, was acting as an allocator > > for these type of devices. > > > > Only compiled tested, so any volunteers willing to test are most welcome. > > I recall an out-of-tree PlayStation 2 OHCI driver being another > HCD_LOCAL_MEM user - if Fredrik and Juergen are still active on that, > hopefully they might be able to comment on whether this approach can > work for them too. Patchwork link just in case: > https://patchwork.kernel.org/project/linux-usb/list/?series=117433 True. In fact I'm preparing a patch submission for this PS2 OHCI driver, along with about a hundred other patches (unrelated to the USB subsystem). Hopefully in a few weeks. My patches are currently on top of v5.0. What branch/version is recommended to try this DMA update? Here is the v5.0.11 PS2 OHCI driver, for reference: https://github.com/frno7/linux/blob/ps2-v5.0.11/drivers/usb/host/ohci-ps2.c Fredrik