usb: core: verify devicetree nodes for disabled interfaces

Message ID 20190507125615.9381-1-m.szyprowski@samsung.com
State New
Headers show
Series
  • usb: core: verify devicetree nodes for disabled interfaces
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Commit Message

Marek Szyprowski May 7, 2019, 12:56 p.m.
Commit 01fdf179f4b0 ("usb: core: skip interfaces disabled in devicetree")
add support for disabling given USB device interface by adding nodes to
the USB host controller device. The mentioned commit however identifies
the given USB interface node only by the 'reg' property in the host
controller children nodes and then checks for their the 'status'. The USB
device interface nodes however also has to have a 'compatible' property as
described in Documentation/devicetree/bindings/usb/usb-device.txt. This is
important, because USB host controller might have child-nodes for other
purposes. For example, Exynos EHCI and OHCI drivers already define
child-nodes for each physical root hub port and assigns respective PHY
controller and parameters for them. This conflicts with the proposed
approach and verifying for the presence of the compatible property fixes
this issue without changing the devicetree bindings and the way the PHY
controllers are handled by Exynos EHCI/OHCI drivers.

Reported-by: Markus Reichl <m.reichl@fivetechno.de>
Fixes: 01fdf179f4b0 ("usb: core: skip interfaces disabled in devicetree")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

---
 drivers/usb/core/message.c | 1 +
 1 file changed, 1 insertion(+)

-- 
2.17.1

Comments

Måns Rullgård May 7, 2019, 1:24 p.m. | #1
Marek Szyprowski <m.szyprowski@samsung.com> writes:

> Commit 01fdf179f4b0 ("usb: core: skip interfaces disabled in devicetree")

> add support for disabling given USB device interface by adding nodes to

> the USB host controller device. The mentioned commit however identifies

> the given USB interface node only by the 'reg' property in the host

> controller children nodes and then checks for their the 'status'. The USB

> device interface nodes however also has to have a 'compatible' property as

> described in Documentation/devicetree/bindings/usb/usb-device.txt. This is

> important, because USB host controller might have child-nodes for other

> purposes. For example, Exynos EHCI and OHCI drivers already define

> child-nodes for each physical root hub port and assigns respective PHY

> controller and parameters for them. This conflicts with the proposed

> approach and verifying for the presence of the compatible property fixes

> this issue without changing the devicetree bindings and the way the PHY

> controllers are handled by Exynos EHCI/OHCI drivers.

>

> Reported-by: Markus Reichl <m.reichl@fivetechno.de>

> Fixes: 01fdf179f4b0 ("usb: core: skip interfaces disabled in devicetree")

> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

> ---

>  drivers/usb/core/message.c | 1 +

>  1 file changed, 1 insertion(+)

>

> diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c

> index 82239f27c4cc..cd455c4add25 100644

> --- a/drivers/usb/core/message.c

> +++ b/drivers/usb/core/message.c

> @@ -2007,6 +2007,7 @@ int usb_set_configuration(struct usb_device *dev, int configuration)

>  		struct usb_interface *intf = cp->interface[i];

>

>  		if (intf->dev.of_node &&

> +		    of_device_is_compatible(intf->dev.of_node, NULL) &&

>  		    !of_device_is_available(intf->dev.of_node)) {

>  			dev_info(&dev->dev, "skipping disabled interface %d\n",

>  				 intf->cur_altsetting->desc.bInterfaceNumber);

> -- 


This doesn't look right.  of_device_is_compatible() with a NULL compat
argument always returns zero.

There also seems to be a broader incompatibility between the generic USB
bindings and the use of child nodes in the Exynos bindings.

-- 
Måns Rullgård

Patch

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 82239f27c4cc..cd455c4add25 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -2007,6 +2007,7 @@  int usb_set_configuration(struct usb_device *dev, int configuration)
 		struct usb_interface *intf = cp->interface[i];
 
 		if (intf->dev.of_node &&
+		    of_device_is_compatible(intf->dev.of_node, NULL) &&
 		    !of_device_is_available(intf->dev.of_node)) {
 			dev_info(&dev->dev, "skipping disabled interface %d\n",
 				 intf->cur_altsetting->desc.bInterfaceNumber);