From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752515AbdHCKHM (ORCPT ); Thu, 3 Aug 2017 06:07:12 -0400 Received: from mail-lf0-f66.google.com ([209.85.215.66]:36346 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752390AbdHCKHH (ORCPT ); Thu, 3 Aug 2017 06:07:07 -0400 From: Johan Hovold To: Christoph Hellwig , Marek Szyprowski , Greg Kroah-Hartman Cc: =?UTF-8?q?Andreas=20F=C3=A4rber?= , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rpi-kernel@lists.infradead.org, Johan Hovold , stable , Robin Murphy , Sricharan R , Stefan Wahren Subject: [PATCH] dma-mapping: skip USB devices when configuring DMA during probe Date: Thu, 3 Aug 2017 12:05:57 +0200 Message-Id: <20170803100557.29249-1-johan@kernel.org> X-Mailer: git-send-email 2.13.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org USB devices use the DMA mask and offset of the controller, which have already been setup when a device is probed. Note that modifying the mask of a USB device would change the mask for the controller (and all devices on the bus) as the mask is literally shared. Since commit 2bf698671205 ("USB: of: fix root-hub device-tree node handling"), of_dma_configure() would be called also for root hubs, which use the device node of the controller. A separate bug that makes of_dma_configure() generate a 30-bit DMA mask from the RPI3's "dma-ranges" would thus set a broken mask also for the controller. This in turn leads to USB devices failing to enumerate when control transfers fail: dwc2 3f980000.usb: Cannot do DMA to address 0x000000003a166a00 Fix this, and similar future problems, by simply skipping USB devices when dma_configure() is called during probe. Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices") Cc: stable # 4.12 Cc: Robin Murphy Cc: Sricharan R Cc: Stefan Wahren Reported-by: Hans Verkuil Signed-off-by: Johan Hovold --- drivers/base/dma-mapping.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index b555ff9dd8fc..c6cde7e79599 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -13,6 +13,7 @@ #include #include #include +#include #include /* @@ -345,6 +346,10 @@ int dma_configure(struct device *dev) enum dev_dma_attr attr; int ret = 0; + /* USB devices share the controller's mask. */ + if (dev->bus == &usb_bus_type) + return 0; + if (dev_is_pci(dev)) { bridge = pci_get_host_bridge_device(to_pci_dev(dev)); dma_dev = bridge; @@ -369,6 +374,9 @@ int dma_configure(struct device *dev) void dma_deconfigure(struct device *dev) { + if (dev->bus == &usb_bus_type) + return; + of_dma_deconfigure(dev); acpi_dma_deconfigure(dev); } -- 2.13.3