USB 2.0 specification chapter 11.17.5 says "as part of endpoint halt
processing for full-/low-speed endpoints connected via a TT, the host
software must use the Clear_TT_Buffer request to the TT to ensure
that the buffer is not in the busy state".
In our case, a full-speed speaker (ConferenceCam) is behind a high-
speed hub (ConferenceCam Connect), sometimes once we get STALL on a
request we may continue to get STALL with the folllowing requests,
like Set_Interface.
Solution is to invoke usb_hub_clear_tt_buffer() to send
Clear_TT_Buffer request to the hub of the device for the following
Set_Interface requests to the device to get ACK successfully.
The Clear_TT_Buffer request sent to the hub includes the address of
the LS/FS child device in wValue field. usb_hub_clear_tt_buffer()
uses udev->devnum to set the address wValue. This won't work for
devices connected to xHC.
For other host controllers udev->devnum is the same as the address of
the usb device, chosen and set by usb core. With xHC the controller
hardware assigns the address, and won't be the same as devnum.
Here we have two patches.
One is to add devaddr in struct usb_device for
usb_hub_clear_tt_buffer() to use.
Another is to update devaddr in XHCI address_device callback
function and invoke usb_hub_clear_tt_buffer() for halt processing.
Signed-off-by: Jim Lin <[email protected]>
Jim Lin (2):
usb: hub : Add devaddr in struct usb_device
usb: xhci: Add Clear_TT_Buffer support
drivers/usb/core/hub.c | 4 +++-
drivers/usb/host/xhci-ring.c | 12 ++++++++++++
drivers/usb/host/xhci.c | 1 +
include/linux/usb.h | 2 ++
4 files changed, 18 insertions(+), 1 deletion(-)
--
2.1.4
The Clear_TT_Buffer request sent to the hub includes the address of
the LS/FS child device in wValue field. usb_hub_clear_tt_buffer()
uses udev->devnum to set the address wValue. This won't work for
devices connected to xHC.
For other host controllers udev->devnum is the same as the address of
the usb device, chosen and set by usb core. With xHC the controller
hardware assigns the address, and won't be the same as devnum.
Here we add devaddr in "struct usb_device" for
usb_hub_clear_tt_buffer() to use.
Signed-off-by: Jim Lin <[email protected]>
---
v2: xhci_clear_tt_buffer_complete: add static, shorter indentation
, remove its claiming in xhci.h
v3: Add description for clearing_tt (xhci.h)
v4: Remove clearing_tt flag because hub_tt_work has hub->tt.lock
to protect for Clear_TT_Buffer to be run serially.
Remove xhci_clear_tt_buffer_complete as it's not necessary.
Same reason as the above.
Extend usb_hub_clear_tt_buffer parameter
v5: Not extending usb_hub_clear_tt_buffer parameter
Add description.
v6: Remove unused parameter slot_id from xhci_clear_hub_tt_buffer
v7: Add devaddr field in "struct usb_device"
v8: split as two patches, change type from int to u8 for devaddr.
drivers/usb/core/hub.c | 4 +++-
include/linux/usb.h | 2 ++
2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 15a2934dc29d..078894023797 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -873,7 +873,7 @@ int usb_hub_clear_tt_buffer(struct urb *urb)
/* info that CLEAR_TT_BUFFER needs */
clear->tt = tt->multi ? udev->ttport : 1;
clear->devinfo = usb_pipeendpoint (pipe);
- clear->devinfo |= udev->devnum << 4;
+ clear->devinfo |= (u16) (udev->devaddr << 4);
clear->devinfo |= usb_pipecontrol(pipe)
? (USB_ENDPOINT_XFER_CONTROL << 11)
: (USB_ENDPOINT_XFER_BULK << 11);
@@ -2125,6 +2125,8 @@ static void update_devnum(struct usb_device *udev, int devnum)
/* The address for a WUSB device is managed by wusbcore. */
if (!udev->wusb)
udev->devnum = devnum;
+ if (!udev->devaddr)
+ udev->devaddr = (u8) devnum;
}
static void hub_free_dev(struct usb_device *udev)
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 4229eb74bd2c..db38c13a6b1d 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -565,6 +565,7 @@ struct usb3_lpm_parameters {
* @tx_lanes: number of tx lanes in use, USB 3.2 adds dual-lane support
* @tt: Transaction Translator info; used with low/full speed dev, highspeed hub
* @ttport: device port on that tt hub
+ * @devaddr: device address, XHCI: assigned by HW, others: same as devnum
* @toggle: one bit for each endpoint, with ([0] = IN, [1] = OUT) endpoints
* @parent: our hub, unless we're the root
* @bus: bus we're part of
@@ -641,6 +642,7 @@ struct usb_device {
struct usb_tt *tt;
int ttport;
+ u8 devaddr;
unsigned int toggle[2];
--
2.1.4
On Fri, May 10, 2019 at 05:02:16PM +0800, Jim Lin wrote:
> The Clear_TT_Buffer request sent to the hub includes the address of
> the LS/FS child device in wValue field. usb_hub_clear_tt_buffer()
> uses udev->devnum to set the address wValue. This won't work for
> devices connected to xHC.
>
> For other host controllers udev->devnum is the same as the address of
> the usb device, chosen and set by usb core. With xHC the controller
> hardware assigns the address, and won't be the same as devnum.
>
> Here we add devaddr in "struct usb_device" for
> usb_hub_clear_tt_buffer() to use.
>
> Signed-off-by: Jim Lin <[email protected]>
> ---
> v2: xhci_clear_tt_buffer_complete: add static, shorter indentation
> , remove its claiming in xhci.h
> v3: Add description for clearing_tt (xhci.h)
> v4: Remove clearing_tt flag because hub_tt_work has hub->tt.lock
> to protect for Clear_TT_Buffer to be run serially.
> Remove xhci_clear_tt_buffer_complete as it's not necessary.
> Same reason as the above.
> Extend usb_hub_clear_tt_buffer parameter
> v5: Not extending usb_hub_clear_tt_buffer parameter
> Add description.
> v6: Remove unused parameter slot_id from xhci_clear_hub_tt_buffer
> v7: Add devaddr field in "struct usb_device"
> v8: split as two patches, change type from int to u8 for devaddr.
>
> drivers/usb/core/hub.c | 4 +++-
> include/linux/usb.h | 2 ++
> 2 files changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
> index 15a2934dc29d..078894023797 100644
> --- a/drivers/usb/core/hub.c
> +++ b/drivers/usb/core/hub.c
> @@ -873,7 +873,7 @@ int usb_hub_clear_tt_buffer(struct urb *urb)
> /* info that CLEAR_TT_BUFFER needs */
> clear->tt = tt->multi ? udev->ttport : 1;
> clear->devinfo = usb_pipeendpoint (pipe);
> - clear->devinfo |= udev->devnum << 4;
> + clear->devinfo |= (u16) (udev->devaddr << 4);
> clear->devinfo |= usb_pipecontrol(pipe)
> ? (USB_ENDPOINT_XFER_CONTROL << 11)
> : (USB_ENDPOINT_XFER_BULK << 11);
> @@ -2125,6 +2125,8 @@ static void update_devnum(struct usb_device *udev, int devnum)
> /* The address for a WUSB device is managed by wusbcore. */
> if (!udev->wusb)
> udev->devnum = devnum;
> + if (!udev->devaddr)
> + udev->devaddr = (u8) devnum;
Checkpatch did not complain here? Or above? Please don't put a space
before the ) when casting.
> }
>
> static void hub_free_dev(struct usb_device *udev)
> diff --git a/include/linux/usb.h b/include/linux/usb.h
> index 4229eb74bd2c..db38c13a6b1d 100644
> --- a/include/linux/usb.h
> +++ b/include/linux/usb.h
> @@ -565,6 +565,7 @@ struct usb3_lpm_parameters {
> * @tx_lanes: number of tx lanes in use, USB 3.2 adds dual-lane support
> * @tt: Transaction Translator info; used with low/full speed dev, highspeed hub
> * @ttport: device port on that tt hub
> + * @devaddr: device address, XHCI: assigned by HW, others: same as devnum
> * @toggle: one bit for each endpoint, with ([0] = IN, [1] = OUT) endpoints
> * @parent: our hub, unless we're the root
> * @bus: bus we're part of
> @@ -641,6 +642,7 @@ struct usb_device {
>
> struct usb_tt *tt;
> int ttport;
> + u8 devaddr;
That's some horrible variable alignment :(
Please use pahole to find a better place to put it.
thanks,
greg k-h