From patchwork Wed Sep 16 06:14:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11779101 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 49614112E for ; Wed, 16 Sep 2020 06:29:35 +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 09231206DB for ; Wed, 16 Sep 2020 06:29:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="qtHfoOjl"; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="kaFJQyPG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 09231206DB 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=S9BiLapRluxTSWBSJD6H5pIHNAs/+0+E3WBaEClpLy0=; b=qtHfoOjlT++c90rZDTZRmD7Jg fG3mjfJmWUqNFQKgnC9pd0qJTwBLpBwBXxN4jcKcCTA29Yrl1MdgsIsUeKWflGNBcAEPowYb854zf zv+nTwRP0Gvf2LWW/X7Ank5CqnMWaatW0+TyXLNfF7KC28FYCau6z5NhJEoeyth5IG+wKd3BbAuLa Pus3Z7yIY9Y7+iBA3otTNJC1ixU+cj4ATEgB3Y0nivv5R57umd/kb6j2pVTVMWh9GJ3qFcHkNydvQ AgA8CFg04rJhejXFWuX7q8VeDRUf/nGJyk4pTgBdM3FpgV5YsKgJKHurPo0ejLxRBh6jqFeMtCk+T Nat31NjCA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kIQvK-000078-IA; Wed, 16 Sep 2020 06:28:10 +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 1kIQvI-00006s-Dt for linux-arm-kernel@merlin.infradead.org; Wed, 16 Sep 2020 06:28:08 +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=Sj9/6zg3jBvpe8GWBJtfj7ccMtl/cKmotOW4AeELf0k=; b=kaFJQyPGFngO1rYezn8V4WHTVt bifyPF57Tk4KW6ZXJihhjLUmUxhyNOZUK4hogmfIPx4IEGF7HmjMlXwQkKqSoC5DKQpOh5mz2TcwA h9nqDo+Hc9Y9pLTBIuIX5O9eFitiNQINnXhnSwQhAzSOotBpjP7fmuWmPg0Y9ZmrdERGPmzxV+V2b AZ/toz2BrsjHtlWvKHpmxhL+b5NqgTFXzS5c3QQEHrKB9waDNeovto1ihomE50eY44nWiFIVDJO+4 QGH2ncs+/Sp2SIcFzjs2cQ98GYmTPQnEHa8fZDL77q5xqeenvtITFLDMI/+OrdxwONe8RJgfDTcCM 4+kjLiaA==; 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 1kIQvG-0007fh-Mj; Wed, 16 Sep 2020 06:28:07 +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: Wed, 16 Sep 2020 08:14:58 +0200 Message-Id: <20200916061500.1970090-6-hch@lst.de> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200916061500.1970090-1-hch@lst.de> References: <20200916061500.1970090-1-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;