[U-Boot] [PATCH] usb: Move determination of TT hub address/port into seperate function

[Hans de Goede]

Hi,

On 18-12-15 02:11, Stefan Brüns wrote:
> Start split and complete split tokens need the hub address and the
> downstream port of the first HS hub (device view).
>
> The core of the function was duplicated in both host/ehci_hcd and
> musb-new/usb-compat.h.
>
> Signed-off-by: Stefan Brüns <stefan.bruens at rwth-aachen.de>

Thanks for working on this, I think I've spotted one small bug though, see comments inline.

> ---
> Obsoletes [PATCH 3/6] usb: dwc2: determine TT hub address and port for split transactions
>
>   common/usb.c                      | 54 +++++++++++++++++++++++++++++++++++++++
>   drivers/usb/host/ehci-hcd.c       | 50 ++++--------------------------------
>   drivers/usb/musb-new/musb_host.c  |  8 +++---
>   drivers/usb/musb-new/usb-compat.h | 53 --------------------------------------
>   include/usb.h                     | 10 ++++++++
>   5 files changed, 74 insertions(+), 101 deletions(-)
>
> diff --git a/common/usb.c b/common/usb.c
> index 700bfc3..1d0a151 100644
> --- a/common/usb.c
> +++ b/common/usb.c
> @@ -1200,4 +1200,58 @@ bool usb_device_has_child_on_port(struct usb_device *parent, int port)
>   #endif
>   }
>
> +#ifdef CONFIG_DM_USB
> +void usb_find_hub_address_port(struct usb_device *udev,
> +			       uint8_t *hub_address, uint8_t *hub_port)
> +{
> +	struct udevice *parent;
> +	struct usb_device *uparent, *ttdev;
> +
> +	/*
> +	 * When called from usb-uclass.c: usb_scan_device() udev->dev points
> +	 * to the parent udevice, not the actual udevice belonging to the
> +	 * udev as the device is not instantiated yet. So when searching
> +	 * for the first usb-2 parent start with udev->dev not
> +	 * udev->dev->parent .
> +	 */
> +	ttdev = udev;
> +	parent = udev->dev;
> +	uparent = dev_get_parent_priv(parent);
> +
> +	while (uparent->speed != USB_SPEED_HIGH) {
> +		struct udevice *dev = parent;
> +
> +		if (device_get_uclass_id(dev->parent) != UCLASS_USB_HUB) {
> +			printf("Error: Cannot find high speed parent of usb-1 device\n");
> +			*hub_address = *hub_port = 0;
> +			return;
> +		}
> +
> +		ttdev = dev_get_parent_priv(dev);
> +		parent = dev->parent;
> +		uparent = dev_get_parent_priv(parent);
> +	}
> +	*hub_address = uparent->devnum;
> +	*hub_port = ttdev->portnr;

This is correct to replace the ehci-code, but lets take a closer look at
the musb-new code below.


> +}
> +#else
> +void usb_find_hub_address_port(struct usb_device *udev,
> +			       uint8_t *hub_address, uint8_t *hub_port)
> +{
> +	/* Find out the nearest parent which is high speed */
> +	while (udev->parent->parent != NULL)
> +		if (udev->parent->speed != USB_SPEED_HIGH) {
> +			udev = udev->parent;
> +		} else {
> +			*hub_address = udev->parent->devnum;
> +			*hub_port = udev->portnr;

Same here.

> +			return;
> +		}
> +
> +	printf("Error: Cannot find high speed parent of usb-1 device\n");
> +	*hub_address = *hub_port = 0;
> +}
> +#endif
> +
> +
>   /* EOF */
> diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
> index c85dbce..0a279e7 100644
> --- a/drivers/usb/host/ehci-hcd.c
> +++ b/drivers/usb/host/ehci-hcd.c
> @@ -279,56 +279,16 @@ static inline u8 ehci_encode_speed(enum usb_device_speed speed)
>   static void ehci_update_endpt2_dev_n_port(struct usb_device *udev,
>   					  struct QH *qh)
>   {
> -	struct usb_device *ttdev;
> -	int parent_devnum;
> +	uint8_t portnr = 0;
> +	uint8_t hubaddr = 0;
>
>   	if (udev->speed != USB_SPEED_LOW && udev->speed != USB_SPEED_FULL)
>   		return;
>
> -	/*
> -	 * For full / low speed devices we need to get the devnum and portnr of
> -	 * the tt, so of the first upstream usb-2 hub, there may be usb-1 hubs
> -	 * in the tree before that one!
> -	 */
> -#ifdef CONFIG_DM_USB
> -	/*
> -	 * When called from usb-uclass.c: usb_scan_device() udev->dev points
> -	 * to the parent udevice, not the actual udevice belonging to the
> -	 * udev as the device is not instantiated yet. So when searching
> -	 * for the first usb-2 parent start with udev->dev not
> -	 * udev->dev->parent .
> -	 */
> -	struct udevice *parent;
> -	struct usb_device *uparent;
> -
> -	ttdev = udev;
> -	parent = udev->dev;
> -	uparent = dev_get_parent_priv(parent);
> -
> -	while (uparent->speed != USB_SPEED_HIGH) {
> -		struct udevice *dev = parent;
> -
> -		if (device_get_uclass_id(dev->parent) != UCLASS_USB_HUB) {
> -			printf("ehci: Error cannot find high-speed parent of usb-1 device\n");
> -			return;
> -		}
> -
> -		ttdev = dev_get_parent_priv(dev);
> -		parent = dev->parent;
> -		uparent = dev_get_parent_priv(parent);
> -	}
> -	parent_devnum = uparent->devnum;
> -#else
> -	ttdev = udev;
> -	while (ttdev->parent && ttdev->parent->speed != USB_SPEED_HIGH)
> -		ttdev = ttdev->parent;
> -	if (!ttdev->parent)
> -		return;
> -	parent_devnum = ttdev->parent->devnum;
> -#endif
> +	usb_find_hub_address_port(udev, &hubaddr, &portnr)
>
> -	qh->qh_endpt2 |= cpu_to_hc32(QH_ENDPT2_PORTNUM(ttdev->portnr) |
> -				     QH_ENDPT2_HUBADDR(parent_devnum));
> +	qh->qh_endpt2 |= cpu_to_hc32(QH_ENDPT2_PORTNUM(portnr) |
> +				     QH_ENDPT2_HUBADDR(hubaddr));
>   }
>
>   static int

<note moved the changes to musb_host.c from here to behind other changes to make
  my comments easier to read>

> diff --git a/drivers/usb/musb-new/usb-compat.h b/drivers/usb/musb-new/usb-compat.h
> index 1c41e2a..760bd78 100644
> --- a/drivers/usb/musb-new/usb-compat.h
> +++ b/drivers/usb/musb-new/usb-compat.h
> @@ -68,38 +68,6 @@ static inline int usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd,
>   }
>
>   #ifdef CONFIG_DM_USB
> -static inline u16 find_tt(struct usb_device *udev)
> -{
> -	struct udevice *parent;
> -	struct usb_device *uparent, *ttdev;
> -
> -	/*
> -	 * When called from usb-uclass.c: usb_scan_device() udev->dev points
> -	 * to the parent udevice, not the actual udevice belonging to the
> -	 * udev as the device is not instantiated yet. So when searching
> -	 * for the first usb-2 parent start with udev->dev not
> -	 * udev->dev->parent .
> -	 */
> -	ttdev = udev;
> -	parent = udev->dev;
> -	uparent = dev_get_parent_priv(parent);
> -
> -	while (uparent->speed != USB_SPEED_HIGH) {
> -		struct udevice *dev = parent;
> -
> -		if (device_get_uclass_id(dev->parent) != UCLASS_USB_HUB) {
> -			printf("musb: Error cannot find high speed parent of usb-1 device\n");
> -			return 0;
> -		}
> -
> -		ttdev = dev_get_parent_priv(dev);
> -		parent = dev->parent;
> -		uparent = dev_get_parent_priv(parent);
> -	}
> -
> -	return (uparent->devnum << 8) | (ttdev->portnr - 1);
> -}
> -

Here in the original musb_new code "ttdev->portnr - 1" is used rather then "just "ttdev->portnr".

>   static inline struct usb_device *usb_dev_get_parent(struct usb_device *udev)
>   {
>   	struct udevice *parent = udev->dev->parent;
> @@ -129,27 +97,6 @@ static inline struct usb_device *usb_dev_get_parent(struct usb_device *udev)
>   	return NULL;
>   }
>   #else
> -static inline u16 find_tt(struct usb_device *dev)
> -{
> -	u8 chid;
> -	u8 hub;
> -
> -	/* Find out the nearest parent which is high speed */
> -	while (dev->parent->parent != NULL)
> -		if (dev->parent->speed != USB_SPEED_HIGH)
> -			dev = dev->parent;
> -		else
> -			break;
> -
> -	/* determine the port address at that hub */
> -	hub = dev->parent->devnum;
> -	for (chid = 0; chid < USB_MAXCHILDREN; chid++)
> -		if (dev->parent->children[chid] == dev)
> -			break;
> -
> -	return (hub << 8) | chid;
> -}
> -

And here for the non DM code the same in a convoluted way (the index is
returned which starts at 0, where as portnr-s start at 1).

>   static inline struct usb_device *usb_dev_get_parent(struct usb_device *dev)
>   {
>   	return dev->parent;
 > diff --git a/drivers/usb/musb-new/musb_host.c b/drivers/usb/musb-new/musb_host.c
 > index 40b9c66..352fa8c 100644
 > --- a/drivers/usb/musb-new/musb_host.c
 > +++ b/drivers/usb/musb-new/musb_host.c
 > @@ -2092,9 +2092,11 @@ int musb_urb_enqueue(
 > }
 > #else
 > if (tt_needed(musb, urb->dev)) {
 > - u16 hub_port = find_tt(urb->dev);
 > - qh->h_addr_reg = (u8) (hub_port >> 8);
 > - qh->h_port_reg = (u8) (hub_port & 0xff);
 > + uint8_t portnr = 0;
 > + uint8_t hubaddr = 0;
 > + usb_find_hub_address_port(udev, &hubaddr, &portnr)
 > + qh->h_addr_reg = hubaddr;
 > + qh->h_port_reg = portnr;
 > }
 > #endif
 > }

So here "qh->h_port_reg = portnr" should be "qh->h_port_reg = portnr - 1"
to compensate for the portnr returned by the new usb_find_hub_address_port
being one higher then the one returned by the old find_tt helper.

> diff --git a/include/usb.h b/include/usb.h
> index 55b9268..6e12876 100644
> --- a/include/usb.h
> +++ b/include/usb.h
> @@ -874,6 +874,16 @@ int legacy_hub_port_reset(struct usb_device *dev, int port,
>
>   int hub_port_reset(struct udevice *dev, int port, unsigned short *portstat);
>
> +/*
> + * Searches for the first HS hub above the given device. If a
> + * HS hub is found, the hub address and the port the device is
> + * connected to is return, as required for SPLIT transactions
> + *
> + * @param: udev full speed or low speed device
> + */
> +void usb_find_hub_address_port(struct usb_device *udev,
> +			       uint8_t *hub_address, uint8_t *hub_port);
> +
>   /**
>    * usb_alloc_new_device() - Allocate a new device
>    *
>

This function is usb-2 controller / hub specific, maybe rename it to:
"usb_find_usb2_hub_address_port" to reflect this ?

Regards,

Hans