Cold plugged USB device was not detected on certain PCIe USB cards
(like Inateck card connected to AM64 EVM or connected to J7200 EVM).
Re-plugging the USB device always gets it enumerated.
This issue was discussed in
https://lore.kernel.org/r/[email protected]
and
https://bugzilla.kernel.org/show_bug.cgi?id=214021
So the suggested solution is to register both root hubs along with the
second hcd for xhci.
RFC Patch series can be found at [1]
Changes from RFC:
1) Mathias identified potential issues with the RFC patch [2] and suggested
the solution to use HCD flags. This series implements it.
[1] -> https://lore.kernel.org/linux-usb/[email protected]/
[2] -> https://lore.kernel.org/linux-usb/[email protected]
Kishon Vijay Abraham I (3):
usb: core: hcd: Modularize HCD stop configuration in usb_stop_hcd()
usb: core: hcd: Add support for deferring roothub registration
xhci: Set HCD flag to defer primary roothub registration
drivers/usb/core/hcd.c | 67 +++++++++++++++++++++++++++--------------
drivers/usb/host/xhci.c | 2 +-
include/linux/usb/hcd.h | 2 ++
3 files changed, 48 insertions(+), 23 deletions(-)
--
2.17.1
Set "HCD_FLAG_DEFER_PRI_RH_REGISTER" to hcd->flags in xhci_run() to defer
registering primary roothub in usb_add_hcd(). This will make sure both
primary roothub and secondary roothub will be registered along with the
second HCD. This is required for cold plugged USB devices to be detected
in certain PCIe USB cards (like Inateck USB card connected to AM64 EVM
or J7200 EVM).
Signed-off-by: Kishon Vijay Abraham I <[email protected]>
Suggested-by: Mathias Nyman <[email protected]>
---
drivers/usb/host/xhci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 3618070eba78..9b7d968022c8 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -644,7 +644,6 @@ int xhci_run(struct usb_hcd *hcd)
/* Start the xHCI host controller running only after the USB 2.0 roothub
* is setup.
*/
-
hcd->uses_new_polling = 1;
if (!usb_hcd_is_primary_hcd(hcd))
return xhci_run_finished(xhci);
@@ -692,6 +691,7 @@ int xhci_run(struct usb_hcd *hcd)
if (ret)
xhci_free_command(xhci, command);
}
+ set_bit(HCD_FLAG_DEFER_PRI_RH_REGISTER, &hcd->flags);
xhci_dbg_trace(xhci, trace_xhci_dbg_init,
"Finished xhci_run for USB2 roothub");
--
2.17.1
Hi,
On 25/08/21 4:21 pm, Kishon Vijay Abraham I wrote:
> Set "HCD_FLAG_DEFER_PRI_RH_REGISTER" to hcd->flags in xhci_run() to defer
> registering primary roothub in usb_add_hcd(). This will make sure both
> primary roothub and secondary roothub will be registered along with the
> second HCD. This is required for cold plugged USB devices to be detected
> in certain PCIe USB cards (like Inateck USB card connected to AM64 EVM
> or J7200 EVM).
>
> Signed-off-by: Kishon Vijay Abraham I <[email protected]>
> Suggested-by: Mathias Nyman <[email protected]>
> ---
> drivers/usb/host/xhci.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index 3618070eba78..9b7d968022c8 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -644,7 +644,6 @@ int xhci_run(struct usb_hcd *hcd)
> /* Start the xHCI host controller running only after the USB 2.0 roothub
> * is setup.
> */
> -
I just realized I've left a spurious space here. While fixing Alan's
comment, I'll fix this one.
Regards,
Kishon
> hcd->uses_new_polling = 1;
> if (!usb_hcd_is_primary_hcd(hcd))
> return xhci_run_finished(xhci);
> @@ -692,6 +691,7 @@ int xhci_run(struct usb_hcd *hcd)
> if (ret)
> xhci_free_command(xhci, command);
> }
> + set_bit(HCD_FLAG_DEFER_PRI_RH_REGISTER, &hcd->flags);
> xhci_dbg_trace(xhci, trace_xhci_dbg_init,
> "Finished xhci_run for USB2 roothub");
>
>