From: Mathias Nyman mathias.nyman@linux.intel.com
commit e1959faf085b004e6c3afaaaa743381f00e7c015 upstream.
Some USB 3.1 enumeration issues were reported after the hub driver removed the minimum 100ms limit for the power-on-good delay.
Since commit 90d28fb53d4a ("usb: core: reduce power-on-good delay time of root hub") the hub driver sets the power-on-delay based on the bPwrOn2PwrGood value in the hub descriptor.
xhci driver has a 20ms bPwrOn2PwrGood value for both roothubs based on xhci spec section 5.4.8, but it's clearly not enough for the USB 3.1 devices, causing enumeration issues.
Tests indicate full 100ms delay is needed.
Reported-by: Walt Jr. Brake mr.yming81@gmail.com Signed-off-by: Mathias Nyman mathias.nyman@linux.intel.com Fixes: 90d28fb53d4a ("usb: core: reduce power-on-good delay time of root hub") Cc: stable stable@vger.kernel.org Link: https://lore.kernel.org/r/20211105160036.549516-1-mathias.nyman@linux.intel.... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/host/xhci-hub.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/usb/host/xhci-hub.c +++ b/drivers/usb/host/xhci-hub.c @@ -156,7 +156,6 @@ static void xhci_common_hub_descriptor(s { u16 temp;
- desc->bPwrOn2PwrGood = 10; /* xhci section 5.4.9 says 20ms max */ desc->bHubContrCurrent = 0;
desc->bNbrPorts = ports; @@ -190,6 +189,7 @@ static void xhci_usb2_hub_descriptor(str desc->bDescriptorType = USB_DT_HUB; temp = 1 + (ports / 8); desc->bDescLength = USB_DT_HUB_NONVAR_SIZE + 2 * temp; + desc->bPwrOn2PwrGood = 10; /* xhci section 5.4.8 says 20ms */
/* The Device Removable bits are reported on a byte granularity. * If the port doesn't exist within that byte, the bit is set to 0. @@ -240,6 +240,7 @@ static void xhci_usb3_hub_descriptor(str xhci_common_hub_descriptor(xhci, desc, ports); desc->bDescriptorType = USB_DT_SS_HUB; desc->bDescLength = USB_DT_SS_HUB_SIZE; + desc->bPwrOn2PwrGood = 50; /* usb 3.1 may fail if less than 100ms */
/* header decode latency should be zero for roothubs, * see section 4.23.5.2.