Patch to fix USB on Raspberry Pi

1 files changed, 127 insertions, 0 deletions

diff --git a/bcm283x-dma-mapping-skip-USB-devices-when-configuring-DMA-during-probe.patch b/bcm283x-dma-mapping-skip-USB-devices-when-configuring-DMA-during-probe.patch
new file mode 100644
index 000000000..c6f7f12de
--- /dev/null
+++ b/bcm283x-dma-mapping-skip-USB-devices-when-configuring-DMA-during-probe.patch
@@ -0,0 +1,127 @@
+From patchwork Thu Aug  3 15:52:08 2017
+Content-Type: text/plain; charset="utf-8"
+MIME-Version: 1.0
+Content-Transfer-Encoding: 7bit
+Subject: [v3] dma-mapping: skip USB devices when configuring DMA during probe
+From: Johan Hovold <johan@kernel.org>
+X-Patchwork-Id: 9879371
+Message-Id: <20170803155208.22165-1-johan@kernel.org>
+To: Christoph Hellwig <hch@lst.de>,
+ Marek Szyprowski <m.szyprowski@samsung.com>,
+ Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+Cc: =?UTF-8?q?Andreas=20F=C3=A4rber?= <afaerber@suse.de>,
+ linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
+ Alan Stern <stern@rowland.harvard.edu>, Johan Hovold <johan@kernel.org>,
+ stable <stable@vger.kernel.org>, Robin Murphy <robin.murphy@arm.com>,
+ Sricharan R <sricharan@codeaurora.org>,
+ Stefan Wahren <stefan.wahren@i2se.com>
+Date: Thu,  3 Aug 2017 17:52:08 +0200
+
+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
+DMA 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, long-standing 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 prevents USB devices from enumerating when control transfers
+fail:
+
+	dwc2 3f980000.usb: Cannot do DMA to address 0x000000003a166a00
+
+Note that the aforementioned DMA-mask bug was benign for the HCD itself
+as the dwc2 driver overwrites the mask previously set by
+of_dma_configure() for the platform device in its probe callback. The
+mask would only later get corrupted when the root-hub child device was
+probed.
+
+Fix this, and similar future problems, by adding a flag to struct device
+which prevents driver core from calling dma_configure() during probe and
+making sure it is set for USB devices.
+
+Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices")
+Cc: stable <stable@vger.kernel.org>	# 4.12
+Cc: Robin Murphy <robin.murphy@arm.com>
+Cc: Sricharan R <sricharan@codeaurora.org>
+Cc: Stefan Wahren <stefan.wahren@i2se.com>
+Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
+Signed-off-by: Johan Hovold <johan@kernel.org>
+---
+
+v3
+ - add flag to struct device to prevent DMA configuration during probe instead
+   of checking for the USB bus type, which is not available when USB is built
+   as a module as noted by Alan
+ - drop moderated rpi list from CC
+
+v2
+ - amend commit message and point out that the long-standing 30-bit DMA-mask
+   bug was benign to the dwc2 HCD itself (Robin)
+ - add and use a new dev_is_usb() helper (Robin)
+
+
+ drivers/base/dma-mapping.c | 6 ++++++
+ drivers/usb/core/usb.c     | 1 +
+ include/linux/device.h     | 3 +++
+ 3 files changed, 10 insertions(+)
+
+diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
+index b555ff9dd8fc..f9f703be0ad1 100644
+--- a/drivers/base/dma-mapping.c
++++ b/drivers/base/dma-mapping.c
+@@ -345,6 +345,9 @@ int dma_configure(struct device *dev)
+ 	enum dev_dma_attr attr;
+ 	int ret = 0;
+ 
++	if (dev->skip_dma_configure)
++		return 0;
++
+ 	if (dev_is_pci(dev)) {
+ 		bridge = pci_get_host_bridge_device(to_pci_dev(dev));
+ 		dma_dev = bridge;
+@@ -369,6 +372,9 @@ int dma_configure(struct device *dev)
+ 
+ void dma_deconfigure(struct device *dev)
+ {
++	if (dev->skip_dma_configure)
++		return;
++
+ 	of_dma_deconfigure(dev);
+ 	acpi_dma_deconfigure(dev);
+ }
+diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
+index 17681d5638ac..2a85d905b539 100644
+--- a/drivers/usb/core/usb.c
++++ b/drivers/usb/core/usb.c
+@@ -588,6 +588,7 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
+ 	 * Note: calling dma_set_mask() on a USB device would set the
+ 	 * mask for the entire HCD, so don't do that.
+ 	 */
++	dev->dev.skip_dma_configure = true;
+ 	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));
+diff --git a/include/linux/device.h b/include/linux/device.h
+index 723cd54b94da..022cf258068b 100644
+--- a/include/linux/device.h
++++ b/include/linux/device.h
+@@ -877,6 +877,8 @@ struct dev_links_info {
+  * @offline:	Set after successful invocation of bus type's .offline().
+  * @of_node_reused: Set if the device-tree node is shared with an ancestor
+  *              device.
++ * @skip_dma_configure: Set if driver core should not configure DMA for this
++ *              device during probe.
+  *
+  * At the lowest level, every device in a Linux system is represented by an
+  * instance of struct device. The device structure contains the information
+@@ -965,6 +967,7 @@ struct device {
+ 	bool			offline_disabled:1;
+ 	bool			offline:1;
+ 	bool			of_node_reused:1;
++	bool			skip_dma_configure:1;
+ };
+ 
+ static inline struct device *kobj_to_dev(struct kobject *kobj)