USB:ehci:fix Kunpeng920 ehci hardware problem
authorLongfang Liu <liulongfang@huawei.com>
Fri, 9 Apr 2021 08:48:01 +0000 (16:48 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 15 Aug 2021 11:01:04 +0000 (13:01 +0200)
commit 26b75952ca0b8b4b3050adb9582c8e2f44d49687 upstream.

Kunpeng920's EHCI controller does not have SBRN register.
Reading the SBRN register when the controller driver is
initialized will get 0.

When rebooting the EHCI driver, ehci_shutdown() will be called.
if the sbrn flag is 0, ehci_shutdown() will return directly.
The sbrn flag being 0 will cause the EHCI interrupt signal to
not be turned off after reboot. this interrupt that is not closed
will cause an exception to the device sharing the interrupt.

Therefore, the EHCI controller of Kunpeng920 needs to skip
the read operation of the SBRN register.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Longfang Liu <liulongfang@huawei.com>
Link: https://lore.kernel.org/r/1617958081-17999-1-git-send-email-liulongfang@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/host/ehci-pci.c

index 08b3f8c806016ce19a3be783928e70189d5eb02b..a31015a95fd64e425b09cd422a294d88c8486f27 100644 (file)
@@ -312,6 +312,9 @@ static int ehci_pci_setup(struct usb_hcd *hcd)
        if (pdev->vendor == PCI_VENDOR_ID_STMICRO
            && pdev->device == PCI_DEVICE_ID_STMICRO_USB_HOST)
                ;       /* ConneXT has no sbrn register */
+       else if (pdev->vendor == PCI_VENDOR_ID_HUAWEI
+                        && pdev->device == 0xa239)
+               ;       /* HUAWEI Kunpeng920 USB EHCI has no sbrn register */
        else
                pci_read_config_byte(pdev, 0x60, &ehci->sbrn);