From: Jose Ignacio Tornos Martinez Date: Wed, 3 Jun 2026 10:58:53 +0000 (+0200) Subject: PCI: Avoid SBR for Qualcomm WCN6855/WCN7850 WiFi, SDX62/SDX65 modems X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6a4f64c3a3ada43e71ef1e06da89beb36bdaeefa;p=thirdparty%2Flinux.git PCI: Avoid SBR for Qualcomm WCN6855/WCN7850 WiFi, SDX62/SDX65 modems Some Qualcomm PCIe devices (WCN6855/WCN7850 WiFi cards, SDX62/SDX65 modems) do not properly support Secondary Bus Reset (SBR). Testing confirms this is device-specific, not deployment-specific: MediaTek MT7925e successfully uses bus reset through the same passive M.2-to-PCIe adapters where Qualcomm devices fail, proving PERST# is properly wired through the adapters. Prevent use of Secondary Bus Reset for these devices. Signed-off-by: Jose Ignacio Tornos Martinez Signed-off-by: Bjorn Helgaas Link: https://lore.kernel.org/all/20260609163649.319755-4-jtornosm@redhat.com --- diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index e49136ac5dbf..431c021d7414 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3790,6 +3790,9 @@ DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003c, quirk_no_bus_reset); DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0033, quirk_no_bus_reset); DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x0034, quirk_no_bus_reset); DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATHEROS, 0x003e, quirk_no_bus_reset); +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_QCOM, 0x1103, quirk_no_bus_reset); /* WCN6855 */ +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_QCOM, 0x1107, quirk_no_bus_reset); /* WCN7850 */ +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_QCOM, 0x0308, quirk_no_bus_reset); /* SDX62/SDX65 */ /* * Root port on some Cavium CN8xxx chips do not successfully complete a bus