On 2021/4/15 22:43, Alan Stern wrote:
> On Thu, Apr 15, 2021 at 08:22:38PM +0800, Longfang Liu wrote:
>> When the number of ports on the USB hub is 0, skip the registration
>> operation of the USB hub.
>>
>> The current Kunpeng930's XHCI hardware controller is defective. The number
>> of ports on its USB3.0 bus controller is 0, and the number of ports on
>> the USB2.0 bus controller is 1.
>>
>> In order to solve this problem that the USB3.0 controller does not have
>> a port which causes the registration of the hub to fail, this patch passes
>> the defect information by adding flags in the quirks of xhci and usb_hcd,
>> and finally skips the registration process of the hub directly according
>> to the results of these flags when the hub is initialized.
>>
>> Signed-off-by: Longfang Liu <liulongf...@huawei.com>
>
> The objections that Greg raised are all good ones.
>
> But even aside from them, this patch doesn't actually do what the
> description says. The patch doesn't remove the call to usb_add_hcd
> for the USB-3 bus. If you simply skipped that call (and the
> corresponding call to usb_remove_hcd) when there are no
> ports on the root hub, none of the stuff in this patch would be needed.
>
> Alan Stern
>
"[RFC PATCH] USB:XHCI:Adjust the log level of hub"
The current method is an improved method of the above patch.
This patch just make it skip registering USB-3 root hub if that hub has no
ports,
after skipping registering, no port will not report error log,the goal of this
patch is reached without error log output.
Thanks.
Longfang.
>> ---
>> drivers/usb/core/hub.c | 6 ++++++
>> drivers/usb/host/xhci-pci.c | 4 ++++
>> drivers/usb/host/xhci.c | 5 +++++
>> drivers/usb/host/xhci.h | 1 +
>> include/linux/usb/hcd.h | 1 +
>> 5 files changed, 17 insertions(+)
>>
>> diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
>> index b1e14be..2d6869d 100644
>> --- a/drivers/usb/core/hub.c
>> +++ b/drivers/usb/core/hub.c
>> @@ -1769,9 +1769,15 @@ static int hub_probe(struct usb_interface *intf,
>> const struct usb_device_id *id)
>> struct usb_host_interface *desc;
>> struct usb_device *hdev;
>> struct usb_hub *hub;
>> + struct usb_hcd *hcd;
>>
>> desc = intf->cur_altsetting;
>> hdev = interface_to_usbdev(intf);
>> + hcd = bus_to_hcd(hdev->bus);
>> + if (hcd->usb3_no_port) {
>> + dev_warn(&intf->dev, "USB hub has no port\n");
>> + return -ENODEV;
>> + }
>>
>> /*
>> * Set default autosuspend delay as 0 to speedup bus suspend,
>> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
>> index ef513c2..63b89a4 100644
>> --- a/drivers/usb/host/xhci-pci.c
>> +++ b/drivers/usb/host/xhci-pci.c
>> @@ -281,6 +281,10 @@ static void xhci_pci_quirks(struct device *dev, struct
>> xhci_hcd *xhci)
>> if (xhci->quirks & XHCI_RESET_ON_RESUME)
>> xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
>> "QUIRK: Resetting on resume");
>> +
>> + if (pdev->vendor == PCI_VENDOR_ID_HUAWEI &&
>> + pdev->device == 0xa23c)
>> + xhci->quirks |= XHCI_USB3_NOPORT;
>> }
>>
>> #ifdef CONFIG_ACPI
>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
>> index bee5dec..e3e3573 100644
>> --- a/drivers/usb/host/xhci.c
>> +++ b/drivers/usb/host/xhci.c
>> @@ -5184,6 +5184,11 @@ int xhci_gen_setup(struct usb_hcd *hcd,
>> xhci_get_quirks_t get_quirks)
>> /* xHCI private pointer was set in xhci_pci_probe for the second
>> * registered roothub.
>> */
>> + if (xhci->quirks & XHCI_USB3_NOPORT) {
>> + xhci_info(xhci, "xHCI host has no port\n");
>> + hcd->usb3_no_port = 1;
>> + }
>> +
>> return 0;
>> }
>>
>> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
>> index 2c6c4f8..d3c658f 100644
>> --- a/drivers/usb/host/xhci.h
>> +++ b/drivers/usb/host/xhci.h
>> @@ -1874,6 +1874,7 @@ struct xhci_hcd {
>> #define XHCI_RESET_PLL_ON_DISCONNECT BIT_ULL(34)
>> #define XHCI_SNPS_BROKEN_SUSPEND BIT_ULL(35)
>> #define XHCI_RENESAS_FW_QUIRK BIT_ULL(36)
>> +#define XHCI_USB3_NOPORT BIT_ULL(37)
>>
>> unsigned int num_active_eps;
>> unsigned int limit_active_eps;
>> diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
>> index 3dbb42c..7df23a0f 100644
>> --- a/include/linux/usb/hcd.h
>> +++ b/include/linux/usb/hcd.h
>> @@ -172,6 +172,7 @@ struct usb_hcd {
>> unsigned tpl_support:1; /* OTG & EH TPL support */
>> unsigned cant_recv_wakeups:1;
>> /* wakeup requests from downstream aren't received */
>> + unsigned usb3_no_port:1; /* xHCI main_hcd has no port */
>>
>> unsigned int irq; /* irq allocated */
>> void __iomem *regs; /* device memory/io */
>> --
>> 2.8.1
>>
> .
>
