From d8490c57b6e2e755c86b678b89d25805347dc29f Mon Sep 17 00:00:00 2001 From: Huacai Chen Date: Sun, 2 Feb 2025 20:49:35 +0800 Subject: [PATCH] USB: pci-quirks: Fix HCCPARAMS register error for LS7A EHCI 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 Signed-off-by: Baoqi Zhang Signed-off-by: Huacai Chen Link: https://lore.kernel.org/r/20250202124935.480500-1-chenhuacai@loongson.cn Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/pci-quirks.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c index 2665832f9add..b96d9062a083 100644 --- a/drivers/usb/host/pci-quirks.c +++ b/drivers/usb/host/pci-quirks.c @@ -946,6 +946,15 @@ static void quirk_usb_disable_ehci(struct pci_dev *pdev) * 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);