From patchwork Mon Sep 14 07:33:42 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11773159 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A388A14F6 for ; Mon, 14 Sep 2020 07:47:05 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5FA1220EDD for ; Mon, 14 Sep 2020 07:47:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="BZaLjiMK"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="iYglZJwL" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5FA1220EDD Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=CmyeApMPo4U72uaeK0CFEzUeiOMsgwrHHneocTUFCYg=; b=BZaLjiMKtMlvXM+k3VOsZ1UTL xqrJkS8Ttbg+pzW/NZ3upYNH+2+Cuta4nDcLD2kVisOhXZdoyCogdITOnWWfZBYC4n14bRXO2IImD KE5QerWRDJcI4rpEiapjgiqbYZ/rOmWESgP2TVMzNbnkY70x39C5goHvrr2lLWcoR5mPne0WJigLI 0eK34xFi+HznCzXiIf1KBhnuGbMg1vHD3JqM9wcn246KhNfRDySN7gOzLhykp34iTGZUAB89mhfXN lyXovib623Fnx6OanjVELfTjLnvbxQ5ZU4m/b73YCsUWKVq7JbRBzQuxzL7QgRHZMeQejNsGeXjrv 4vHbh2++Q==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kHjCP-0003lv-7B; Mon, 14 Sep 2020 07:46:53 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kHjCM-0003lf-U7 for linux-arm-kernel@merlin.infradead.org; Mon, 14 Sep 2020 07:46:50 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=cPqBYq5povPLhzEYOyx5GvOLRCGW66TTAZJ+daEl52w=; b=iYglZJwLzk6QChePoSrmhAvdyb l78kJNSRO4PN+2+9URpPa8neGWWEj7PxXZ/bHrsB+MsIqClcOch1s/2XUgxIGUtH5LvyKkrFwDUEP +0sFvvHDKcLTp5piUcWx6pOtDO23awiYO28M27zgm9fpp5ooxb6sqXJQ0YpXVMfu23lBBXBDLZSzz mdGXvTHW146h81v/e/y2f0jZ3u2B6l2Kkvwni1Ib51JpQuUL5o4ERZ1jFtaF6HPLhhVnR7bbySC2K 3Ach0o1ngE2FF91LbR/lApduf2NtE5av39CaFEMyb0KdHTNoL6OYRuQq0zSxAv3N5oVDl2sMf+pxq GVApXDgg==; Received: from 089144214092.atnat0023.highway.a1.net ([89.144.214.92] helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kHjCL-0000c0-Hb; Mon, 14 Sep 2020 07:46:49 +0000 From: Christoph Hellwig To: iommu@lists.linux-foundation.org, Russell King , Santosh Shilimkar , Greg Kroah-Hartman Subject: [PATCH 5/6] usb: don't inherity DMA properties for USB devices Date: Mon, 14 Sep 2020 09:33:42 +0200 Message-Id: <20200914073343.1579578-6-hch@lst.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200914073343.1579578-1-hch@lst.de> References: <20200914073343.1579578-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ohad Ben-Cohen , devicetree@vger.kernel.org, Florian Fainelli , linux-sh@vger.kernel.org, Frank Rowand , linux-usb@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, Bjorn Andersson , linux-acpi@vger.kernel.org, Rob Herring , Jim Quinlan , linux-pci@vger.kernel.org, Nathan Chancellor , Robin Murphy , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org As the comment in usb_alloc_dev correctly states, drivers can't use the DMA API on usb device, and at least calling dma_set_mask on them is highly dangerous. Unlike what the comment states upper level drivers also can't really use the presence of a dma mask to check for DMA support, as the dma_mask is set by default for most busses. Setting the dma_mask comes from "[PATCH] usbcore dma updates (and doc)" in BitKeeper times, as it seems like it was primarily for setting the NETIF_F_HIGHDMA flag in USB drivers, something that has long been fixed up since. Setting the dma_pfn_offset comes from commit b44bbc46a8bb ("usb: core: setup dma_pfn_offset for USB devices and, interfaces"), which worked around the fact that the scsi_calculate_bounce_limits functions wasn't going through the proper driver interface to query DMA information, but that function was removed in commit 21e07dba9fb1 ("scsi: reduce use of block bounce buffers") years ago. Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman --- drivers/usb/core/message.c | 6 ------ drivers/usb/core/usb.c | 12 ------------ 2 files changed, 18 deletions(-) diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c index 6197938dcc2d8f..9e45732dc1d1d1 100644 --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1954,12 +1954,6 @@ int usb_set_configuration(struct usb_device *dev, int configuration) intf->dev.bus = &usb_bus_type; intf->dev.type = &usb_if_device_type; intf->dev.groups = usb_interface_groups; - /* - * Please refer to usb_alloc_dev() to see why we set - * dma_mask and dma_pfn_offset. - */ - intf->dev.dma_mask = dev->dev.dma_mask; - intf->dev.dma_pfn_offset = dev->dev.dma_pfn_offset; INIT_WORK(&intf->reset_ws, __usb_queue_reset_device); intf->minor = -1; device_initialize(&intf->dev); diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index bafc113f2b3ef3..9b4ac4415f1a47 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -599,18 +599,6 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent, dev->dev.bus = &usb_bus_type; dev->dev.type = &usb_device_type; dev->dev.groups = usb_device_groups; - /* - * Fake a dma_mask/offset for the USB device: - * We cannot really use the dma-mapping API (dma_alloc_* and - * dma_map_*) for USB devices but instead need to use - * usb_alloc_coherent and pass data in 'urb's, but some subsystems - * manually look into the mask/offset pair to determine whether - * they need bounce buffers. - * Note: calling dma_set_mask() on a USB device would set the - * mask for the entire HCD, so don't do that. - */ - dev->dev.dma_mask = bus->sysdev->dma_mask; - dev->dev.dma_pfn_offset = bus->sysdev->dma_pfn_offset; set_dev_node(&dev->dev, dev_to_node(bus->sysdev)); dev->state = USB_STATE_ATTACHED; dev->lpm_disable_count = 1;