5.15-stable review patch. If anyone has any objections, please let me know.
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From: Huacai Chen chenhuacai@loongson.cn
commit e71f7f42e3c874ac3314b8f250e8416a706165af upstream.
LS7A EHCI controller doesn't have extended capabilities, so the EECP (EHCI Extended Capabilities Pointer) field of HCCPARAMS register should be 0x0, but it reads as 0xa0 now. This is a hardware flaw and will be fixed in future, now just clear the EECP field to avoid error messages on boot:
...... [ 0.581675] pci 0000:00:04.1: EHCI: unrecognized capability ff [ 0.581699] pci 0000:00:04.1: EHCI: unrecognized capability ff [ 0.581716] pci 0000:00:04.1: EHCI: unrecognized capability ff [ 0.581851] pci 0000:00:04.1: EHCI: unrecognized capability ff ...... [ 0.581916] pci 0000:00:05.1: EHCI: unrecognized capability ff [ 0.581951] pci 0000:00:05.1: EHCI: unrecognized capability ff [ 0.582704] pci 0000:00:05.1: EHCI: unrecognized capability ff [ 0.582799] pci 0000:00:05.1: EHCI: unrecognized capability ff ......
Cc: stable stable@kernel.org Signed-off-by: Baoqi Zhang zhangbaoqi@loongson.cn Signed-off-by: Huacai Chen chenhuacai@loongson.cn Link: https://lore.kernel.org/r/20250202124935.480500-1-chenhuacai@loongson.cn Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/host/pci-quirks.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/drivers/usb/host/pci-quirks.c +++ b/drivers/usb/host/pci-quirks.c @@ -948,6 +948,15 @@ static void quirk_usb_disable_ehci(struc * booting from USB disk or using a usb keyboard */ hcc_params = readl(base + EHCI_HCC_PARAMS); + + /* LS7A EHCI controller doesn't have extended capabilities, the + * EECP (EHCI Extended Capabilities Pointer) field of HCCPARAMS + * register should be 0x0 but it reads as 0xa0. So clear it to + * avoid error messages on boot. + */ + if (pdev->vendor == PCI_VENDOR_ID_LOONGSON && pdev->device == 0x7a14) + hcc_params &= ~(0xffL << 8); + offset = (hcc_params >> 8) & 0xff; while (offset && --count) { pci_read_config_dword(pdev, offset, &cap);