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=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 3D2C7C43219 for ; Thu, 25 Apr 2019 16:27:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 878A920891 for ; Thu, 25 Apr 2019 16:27:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=mev.co.uk header.i=@mev.co.uk header.b="QiituQgV" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730170AbfDYQ1C (ORCPT ); Thu, 25 Apr 2019 12:27:02 -0400 Received: from smtp65.iad3b.emailsrvr.com ([146.20.161.65]:39171 "EHLO smtp65.iad3b.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726542AbfDYQ1B (ORCPT ); Thu, 25 Apr 2019 12:27:01 -0400 Received: from smtp17.relay.iad3b.emailsrvr.com (localhost [127.0.0.1]) by smtp17.relay.iad3b.emailsrvr.com (SMTP Server) with ESMTP id CA144A022E; Thu, 25 Apr 2019 12:26:59 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mev.co.uk; s=20190130-41we5z8j; t=1556209619; bh=JI0XIHBU944Daf061jg6qIdec6ZhsmfJN1xDmjGPOes=; h=From:To:Subject:Date:From; b=QiituQgV8ha47rzKsKLUPyscJuK1T/VkROyOZ3bYIrYjV+caBO95mbV6XUeQbELro wbcXGnUffVjC+jrj7zW+k3bIPfKRQXNvnqzlPz2CGiHCOA7zCRaB2L4lk2TokqWE5p BpC76vubySBDw4iyOMZ1mGKmZgbhbTbDJTYBjuo8= X-Auth-ID: abbotti@mev.co.uk Received: by smtp17.relay.iad3b.emailsrvr.com (Authenticated sender: abbotti-AT-mev.co.uk) with ESMTPSA id 06358A0184; Thu, 25 Apr 2019 12:26:58 -0400 (EDT) X-Sender-Id: abbotti@mev.co.uk Received: from ian-deb.inside.mev.co.uk (remote.quintadena.com [81.133.34.160]) (using TLSv1.2 with cipher DHE-RSA-AES128-GCM-SHA256) by 0.0.0.0:465 (trex/5.7.12); Thu, 25 Apr 2019 12:26:59 -0400 From: Ian Abbott To: devel@driverdev.osuosl.org Cc: Greg Kroah-Hartman , Ian Abbott , H Hartley Sweeten , linux-kernel@vger.kernel.org Subject: [PATCH] staging: comedi: comedi_isadma: Use a non-NULL device for DMA API Date: Thu, 25 Apr 2019 17:26:44 +0100 Message-Id: <20190425162644.21947-1-abbotti@mev.co.uk> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The "comedi_isadma" module calls `dma_alloc_coherent()` and `dma_free_coherent()` with a NULL device pointer which is no longer allowed. If the `hw_dev` member of the `struct comedi_device` has been set to a valid device, that can be used instead. Unfortunately, all the current users of the "comedi_isadma" module leave the `hw_dev` member set to NULL. In that case, use a static dummy fallback device structure with the coherent DMA mask set to the ISA bus limit of 16MB. Signed-off-by: Ian Abbott --- drivers/staging/comedi/drivers/comedi_isadma.c | 15 +++++++++++++-- drivers/staging/comedi/drivers/comedi_isadma.h | 3 +++ 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/staging/comedi/drivers/comedi_isadma.c b/drivers/staging/comedi/drivers/comedi_isadma.c index b77dc8d5d3ff..8929952516a1 100644 --- a/drivers/staging/comedi/drivers/comedi_isadma.c +++ b/drivers/staging/comedi/drivers/comedi_isadma.c @@ -14,6 +14,16 @@ #include "comedi_isadma.h" +/* + * Fallback device used when hardware device is NULL. + * This can be removed after drivers have been converted to use isa_driver. + */ +static struct device fallback_dev = { + .init_name = "comedi_isadma fallback device", + .coherent_dma_mask = DMA_BIT_MASK(24), + .dma_mask = &fallback_dev.coherent_dma_mask, +}; + /** * comedi_isadma_program - program and enable an ISA DMA transfer * @desc: the ISA DMA cookie to program and enable @@ -172,6 +182,7 @@ struct comedi_isadma *comedi_isadma_alloc(struct comedi_device *dev, goto no_dma; dma->desc = desc; dma->n_desc = n_desc; + dma->dev = dev->hw_dev ? dev->hw_dev : &fallback_dev; dma_chans[0] = dma_chan1; if (dma_chan2 == 0 || dma_chan2 == dma_chan1) @@ -192,7 +203,7 @@ struct comedi_isadma *comedi_isadma_alloc(struct comedi_device *dev, desc = &dma->desc[i]; desc->chan = dma_chans[i]; desc->maxsize = maxsize; - desc->virt_addr = dma_alloc_coherent(NULL, desc->maxsize, + desc->virt_addr = dma_alloc_coherent(dma->dev, desc->maxsize, &desc->hw_addr, GFP_KERNEL); if (!desc->virt_addr) @@ -224,7 +235,7 @@ void comedi_isadma_free(struct comedi_isadma *dma) for (i = 0; i < dma->n_desc; i++) { desc = &dma->desc[i]; if (desc->virt_addr) - dma_free_coherent(NULL, desc->maxsize, + dma_free_coherent(dma->dev, desc->maxsize, desc->virt_addr, desc->hw_addr); } diff --git a/drivers/staging/comedi/drivers/comedi_isadma.h b/drivers/staging/comedi/drivers/comedi_isadma.h index 2bd1329d727f..9d2b12db7e6e 100644 --- a/drivers/staging/comedi/drivers/comedi_isadma.h +++ b/drivers/staging/comedi/drivers/comedi_isadma.h @@ -10,6 +10,7 @@ #include struct comedi_device; +struct device; /* * These are used to avoid issues when and the DMA_MODE_ @@ -38,6 +39,7 @@ struct comedi_isadma_desc { /** * struct comedi_isadma - ISA DMA data + * @dev: device to allocate non-coherent memory for * @desc: cookie for each DMA buffer * @n_desc: the number of cookies * @cur_dma: the current cookie in use @@ -45,6 +47,7 @@ struct comedi_isadma_desc { * @chan2: the second DMA channel requested */ struct comedi_isadma { + struct device *dev; struct comedi_isadma_desc *desc; int n_desc; int cur_dma; -- 2.20.1