[PATCH] USB: pci-quirks: Fix HCCPARAMS register error for LS7A EHCI
From: Huacai Chen <hidden>
Date: 2025-01-31 10:07:01
Also in:
lkml, stable
Subsystem:
pci subsystem, the rest, usb subsystem, usb xhci driver · Maintainers:
Bjorn Helgaas, Linus Torvalds, Greg Kroah-Hartman, Mathias Nyman
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@vger.kernel.org Signed-off-by: Baoqi Zhang <redacted> Signed-off-by: Huacai Chen <redacted> --- drivers/usb/host/pci-quirks.c | 4 ++++ include/linux/pci_ids.h | 1 + 2 files changed, 5 insertions(+)
diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 1f9c1b1435d8..7e3151400a5e 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c@@ -958,6 +958,10 @@ 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); + if (pdev->vendor == PCI_VENDOR_ID_LOONGSON && + pdev->device == PCI_DEVICE_ID_LOONGSON_EHCI) + hcc_params &= ~(0xffL << 8); + offset = (hcc_params >> 8) & 0xff; while (offset && --count) { pci_read_config_dword(pdev, offset, &cap);
diff --git a/include/linux/pci_ids.h b/include/linux/pci_ids.h
index de5deb1a0118..74a84834d9eb 100644
--- a/include/linux/pci_ids.h
+++ b/include/linux/pci_ids.h@@ -162,6 +162,7 @@ #define PCI_VENDOR_ID_LOONGSON 0x0014 +#define PCI_DEVICE_ID_LOONGSON_EHCI 0x7a14 #define PCI_DEVICE_ID_LOONGSON_HDA 0x7a07 #define PCI_DEVICE_ID_LOONGSON_HDMI 0x7a37
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2.47.1