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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 autolearn=no 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 32118C432C1 for ; Tue, 24 Sep 2019 21:59:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C8D802168B for ; Tue, 24 Sep 2019 21:59:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="O8XMN3kd"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=hansenpartnership.com header.i=@hansenpartnership.com header.b="O8XMN3kd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403877AbfIXV7b (ORCPT ); Tue, 24 Sep 2019 17:59:31 -0400 Received: from bedivere.hansenpartnership.com ([66.63.167.143]:45924 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387723AbfIXV7b (ORCPT ); Tue, 24 Sep 2019 17:59:31 -0400 Received: from localhost (localhost [127.0.0.1]) by bedivere.hansenpartnership.com (Postfix) with ESMTP id B3C5D8EE175; Tue, 24 Sep 2019 14:59:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1569362370; bh=uW9yHyVMd+iv3gWkWuuWS6RrXxoBB+KwpZEHrxJLrfU=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=O8XMN3kdXIPTbxUwCC+yvDgCK6kxoQ1AVgYkJ3sHY0B5I/tYLPbKdY8Zk15WXAxpf nwOM1LWs7pDqIvECsh37FfhhcQF2MB6rU0bgRPJ88mgbZl+QozFGBn/85UNOQgEsRV GpZpqSAngHQDlDv5BxxAWcKCvDenp3nYP/wIPshs= Received: from bedivere.hansenpartnership.com ([127.0.0.1]) by localhost (bedivere.hansenpartnership.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id yKFYae1JZIO6; Tue, 24 Sep 2019 14:59:30 -0700 (PDT) Received: from [192.168.101.242] (unknown [24.246.103.29]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by bedivere.hansenpartnership.com (Postfix) with ESMTPSA id E1F5E8EE12C; Tue, 24 Sep 2019 14:59:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=hansenpartnership.com; s=20151216; t=1569362370; bh=uW9yHyVMd+iv3gWkWuuWS6RrXxoBB+KwpZEHrxJLrfU=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=O8XMN3kdXIPTbxUwCC+yvDgCK6kxoQ1AVgYkJ3sHY0B5I/tYLPbKdY8Zk15WXAxpf nwOM1LWs7pDqIvECsh37FfhhcQF2MB6rU0bgRPJ88mgbZl+QozFGBn/85UNOQgEsRV GpZpqSAngHQDlDv5BxxAWcKCvDenp3nYP/wIPshs= Message-ID: <1569362368.5364.19.camel@HansenPartnership.com> Subject: Re: allow larger than require DMA masks From: James Bottomley To: Christoph Hellwig Cc: Sven Schnelle , Helge Deller , linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org Date: Tue, 24 Sep 2019 17:59:28 -0400 In-Reply-To: <20190924212554.GA31357@lst.de> References: <20190215144559.8777-1-hch@lst.de> <20190923211415.GA1875@stackframe.org> <1569286782.3657.29.camel@HansenPartnership.com> <20190924212554.GA31357@lst.de> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.26.6 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On Tue, 2019-09-24 at 23:25 +0200, Christoph Hellwig wrote: > On Mon, Sep 23, 2019 at 08:59:42PM -0400, James Bottomley wrote: > > > if (mask > ~0U) > > > » » return 0; > > > > > > Removing the if() makes the DMA mapping work. It's almost > > > midnight here, so i won't look into that any further today. Does > > > anyone have an opinion on this behaviour? Otherwise i will look a > > > bit more into this in the next days. > > > > The reason for the if was to kick the device into 32 bit > > descriptors, which are usually more efficient, especially with > > older dual descriptor format cards like we have on parisc systems. > > These days we use the dma_get_required_mask API to query for that. It looks like sym53c8xx didn't get the memo. On the other hand, I'm fairly certain it should be compiled in addressing mode zero on all parisc systems (since all the 64 bit ones have iommus), so I think we can take care of this ourselves. > Svens patch looks right for how we are now using the DMA mask setting > API. Agreed. James