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 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 <[email protected]> # 4.12
Cc: Robin Murphy <[email protected]>
Cc: Sricharan R <[email protected]>
Cc: Stefan Wahren <[email protected]>
Reported-by: Hans Verkuil <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>
---
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 | 8 ++++++++
include/linux/usb.h | 5 +++++
2 files changed, 13 insertions(+)
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index b555ff9dd8fc..604e99e6660a 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -13,6 +13,7 @@
#include <linux/gfp.h>
#include <linux/of_device.h>
#include <linux/slab.h>
+#include <linux/usb.h>
#include <linux/vmalloc.h>
/*
@@ -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_is_usb(dev))
+ 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_is_usb(dev))
+ return;
+
of_dma_deconfigure(dev);
acpi_dma_deconfigure(dev);
}
diff --git a/include/linux/usb.h b/include/linux/usb.h
index cb9fbd54386e..f86ad9d8c756 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1222,6 +1222,11 @@ struct usb_device_driver {
extern struct bus_type usb_bus_type;
+static inline bool dev_is_usb(struct device *dev)
+{
+ return dev->bus == &usb_bus_type;
+}
+
/**
* struct usb_class_driver - identifies a USB driver that wants to use the USB major number
* @name: the usb class device name for this driver. Will show up in sysfs.
--
2.13.3
On 03/08/17 14:14, Johan Hovold wrote:
> 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 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 <[email protected]> # 4.12
> Cc: Robin Murphy <[email protected]>
> Cc: Sricharan R <[email protected]>
> Cc: Stefan Wahren <[email protected]>
> Reported-by: Hans Verkuil <[email protected]>
> Signed-off-by: Johan Hovold <[email protected]>
Reviewed-by: Robin Murphy <[email protected]>
> ---
>
> 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 | 8 ++++++++
> include/linux/usb.h | 5 +++++
> 2 files changed, 13 insertions(+)
>
> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> index b555ff9dd8fc..604e99e6660a 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -13,6 +13,7 @@
> #include <linux/gfp.h>
> #include <linux/of_device.h>
> #include <linux/slab.h>
> +#include <linux/usb.h>
> #include <linux/vmalloc.h>
>
> /*
> @@ -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_is_usb(dev))
> + 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_is_usb(dev))
> + return;
> +
> of_dma_deconfigure(dev);
> acpi_dma_deconfigure(dev);
> }
> diff --git a/include/linux/usb.h b/include/linux/usb.h
> index cb9fbd54386e..f86ad9d8c756 100644
> --- a/include/linux/usb.h
> +++ b/include/linux/usb.h
> @@ -1222,6 +1222,11 @@ struct usb_device_driver {
>
> extern struct bus_type usb_bus_type;
>
> +static inline bool dev_is_usb(struct device *dev)
> +{
> + return dev->bus == &usb_bus_type;
> +}
> +
> /**
> * struct usb_class_driver - identifies a USB driver that wants to use the USB major number
> * @name: the usb class device name for this driver. Will show up in sysfs.
>
On Thu, 3 Aug 2017, Johan Hovold wrote:
> 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 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 <[email protected]> # 4.12
> Cc: Robin Murphy <[email protected]>
> Cc: Sricharan R <[email protected]>
> Cc: Stefan Wahren <[email protected]>
> Reported-by: Hans Verkuil <[email protected]>
> Signed-off-by: Johan Hovold <[email protected]>
> ---
>
> 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)
> diff --git a/include/linux/usb.h b/include/linux/usb.h
> index cb9fbd54386e..f86ad9d8c756 100644
> --- a/include/linux/usb.h
> +++ b/include/linux/usb.h
> @@ -1222,6 +1222,11 @@ struct usb_device_driver {
>
> extern struct bus_type usb_bus_type;
>
> +static inline bool dev_is_usb(struct device *dev)
> +{
> + return dev->bus == &usb_bus_type;
> +}
> +
Will this work if the USB subsystem is built as a module?
Alan Stern
On Thu, Aug 03, 2017 at 10:04:21AM -0400, Alan Stern wrote:
> On Thu, 3 Aug 2017, Johan Hovold wrote:
>
> > 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 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 <[email protected]> # 4.12
> > Cc: Robin Murphy <[email protected]>
> > Cc: Sricharan R <[email protected]>
> > Cc: Stefan Wahren <[email protected]>
> > Reported-by: Hans Verkuil <[email protected]>
> > Signed-off-by: Johan Hovold <[email protected]>
> > ---
> > diff --git a/include/linux/usb.h b/include/linux/usb.h
> > index cb9fbd54386e..f86ad9d8c756 100644
> > --- a/include/linux/usb.h
> > +++ b/include/linux/usb.h
> > @@ -1222,6 +1222,11 @@ struct usb_device_driver {
> >
> > extern struct bus_type usb_bus_type;
> >
> > +static inline bool dev_is_usb(struct device *dev)
> > +{
> > + return dev->bus == &usb_bus_type;
> > +}
> > +
>
> Will this work if the USB subsystem is built as a module?
Nope. :-/
Add another flag (e.g. skip_dma_configure) to struct device for now?
Thanks,
Johan
On 03/08/17 15:23, Johan Hovold wrote:
> On Thu, Aug 03, 2017 at 10:04:21AM -0400, Alan Stern wrote:
>> On Thu, 3 Aug 2017, Johan Hovold wrote:
>>
>>> 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 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 <[email protected]> # 4.12
>>> Cc: Robin Murphy <[email protected]>
>>> Cc: Sricharan R <[email protected]>
>>> Cc: Stefan Wahren <[email protected]>
>>> Reported-by: Hans Verkuil <[email protected]>
>>> Signed-off-by: Johan Hovold <[email protected]>
>>> ---
>
>>> diff --git a/include/linux/usb.h b/include/linux/usb.h
>>> index cb9fbd54386e..f86ad9d8c756 100644
>>> --- a/include/linux/usb.h
>>> +++ b/include/linux/usb.h
>>> @@ -1222,6 +1222,11 @@ struct usb_device_driver {
>>>
>>> extern struct bus_type usb_bus_type;
>>>
>>> +static inline bool dev_is_usb(struct device *dev)
>>> +{
>>> + return dev->bus == &usb_bus_type;
>>> +}
>>> +
>>
>> Will this work if the USB subsystem is built as a module?
>
> Nope. :-/
Oh bum, I hadn't even realised usb_bus_type could be modular.
> Add another flag (e.g. skip_dma_configure) to struct device for now?
Would it be sufficient to look for dev->of_node_reused, or is it also
possible for USB devices to have OF nodes of their own such that
of_dma_configure() would still blat the mask with a 32-bit default?
(Although that would still un-break Rpi3, even if strictly wrong)
Robin.
On Thu, Aug 03, 2017 at 04:23:08PM +0200, Johan Hovold wrote:
> On Thu, Aug 03, 2017 at 10:04:21AM -0400, Alan Stern wrote:
> > On Thu, 3 Aug 2017, Johan Hovold wrote:
> >
> > > 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 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 <[email protected]> # 4.12
> > > Cc: Robin Murphy <[email protected]>
> > > Cc: Sricharan R <[email protected]>
> > > Cc: Stefan Wahren <[email protected]>
> > > Reported-by: Hans Verkuil <[email protected]>
> > > Signed-off-by: Johan Hovold <[email protected]>
> > > ---
>
> > > diff --git a/include/linux/usb.h b/include/linux/usb.h
> > > index cb9fbd54386e..f86ad9d8c756 100644
> > > --- a/include/linux/usb.h
> > > +++ b/include/linux/usb.h
> > > @@ -1222,6 +1222,11 @@ struct usb_device_driver {
> > >
> > > extern struct bus_type usb_bus_type;
> > >
> > > +static inline bool dev_is_usb(struct device *dev)
> > > +{
> > > + return dev->bus == &usb_bus_type;
> > > +}
> > > +
> >
> > Will this work if the USB subsystem is built as a module?
>
> Nope. :-/
>
> Add another flag (e.g. skip_dma_configure) to struct device for now?
Or we can make sure that of_dma_configure() is only ever called for
platform_devices by checking against platform_bus_type instead.
I guess this was the intention of 09515ef5ddad ("of/acpi: Configure dma
operations at probe time for platform/amba/pci bus devices") too.
Thanks,
Johan
On Thu, Aug 03, 2017 at 03:48:06PM +0100, Robin Murphy wrote:
> On 03/08/17 15:23, Johan Hovold wrote:
> > On Thu, Aug 03, 2017 at 10:04:21AM -0400, Alan Stern wrote:
> >> On Thu, 3 Aug 2017, Johan Hovold wrote:
> >>> diff --git a/include/linux/usb.h b/include/linux/usb.h
> >>> index cb9fbd54386e..f86ad9d8c756 100644
> >>> --- a/include/linux/usb.h
> >>> +++ b/include/linux/usb.h
> >>> @@ -1222,6 +1222,11 @@ struct usb_device_driver {
> >>>
> >>> extern struct bus_type usb_bus_type;
> >>>
> >>> +static inline bool dev_is_usb(struct device *dev)
> >>> +{
> >>> + return dev->bus == &usb_bus_type;
> >>> +}
> >>> +
> >>
> >> Will this work if the USB subsystem is built as a module?
> >
> > Nope. :-/
>
> Oh bum, I hadn't even realised usb_bus_type could be modular.
>
> > Add another flag (e.g. skip_dma_configure) to struct device for now?
>
> Would it be sufficient to look for dev->of_node_reused, or is it also
> possible for USB devices to have OF nodes of their own such that
> of_dma_configure() would still blat the mask with a 32-bit default?
> (Although that would still un-break Rpi3, even if strictly wrong)
Yes, USB devices can have their own OF nodes so of_node_reused would not
prevent of_dma_configure() from being called for them.
But testing against the platform bus instead of not-USB should do the
trick.
Johan
On Thu, Aug 03, 2017 at 04:49:24PM +0200, Johan Hovold wrote:
> On Thu, Aug 03, 2017 at 04:23:08PM +0200, Johan Hovold wrote:
> > On Thu, Aug 03, 2017 at 10:04:21AM -0400, Alan Stern wrote:
> > > On Thu, 3 Aug 2017, Johan Hovold wrote:
> > >
> > > > 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 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 <[email protected]> # 4.12
> > > > Cc: Robin Murphy <[email protected]>
> > > > Cc: Sricharan R <[email protected]>
> > > > Cc: Stefan Wahren <[email protected]>
> > > > Reported-by: Hans Verkuil <[email protected]>
> > > > Signed-off-by: Johan Hovold <[email protected]>
> > > > ---
> >
> > > > diff --git a/include/linux/usb.h b/include/linux/usb.h
> > > > index cb9fbd54386e..f86ad9d8c756 100644
> > > > --- a/include/linux/usb.h
> > > > +++ b/include/linux/usb.h
> > > > @@ -1222,6 +1222,11 @@ struct usb_device_driver {
> > > >
> > > > extern struct bus_type usb_bus_type;
> > > >
> > > > +static inline bool dev_is_usb(struct device *dev)
> > > > +{
> > > > + return dev->bus == &usb_bus_type;
> > > > +}
> > > > +
> > >
> > > Will this work if the USB subsystem is built as a module?
> >
> > Nope. :-/
> >
> > Add another flag (e.g. skip_dma_configure) to struct device for now?
>
> Or we can make sure that of_dma_configure() is only ever called for
> platform_devices by checking against platform_bus_type instead.
>
> I guess this was the intention of 09515ef5ddad ("of/acpi: Configure dma
> operations at probe time for platform/amba/pci bus devices") too.
Or perhaps not, as of_dma_configure() should also be called for pci
devices.
I suggest adding a new flag to struct device.
Johan
Hi Johan,
[auto build test ERROR on driver-core/driver-core-testing]
[also build test ERROR on v4.13-rc3 next-20170804]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Johan-Hovold/dma-mapping-skip-USB-devices-when-configuring-DMA-during-probe/20170804-155414
config: x86_64-randconfig-a0-08061415 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All errors (new ones prefixed by >>):
drivers/base/dma-mapping.o: In function `dma_configure':
>> (.text+0x7de): undefined reference to `usb_bus_type'
drivers/base/dma-mapping.o: In function `dma_deconfigure':
(.text+0x8ca): undefined reference to `usb_bus_type'
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation