git: 4c0e53aced22 - main - pci: add quirk to disable Function-Level Reset (FLR)

The branch main has been updated by bz:

URL: https://cgit.FreeBSD.org/src/commit/?id=4c0e53aced2251eb5ac7eca44e13a6b947be8582

commit 4c0e53aced2251eb5ac7eca44e13a6b947be8582
Author:     Bjoern A. Zeeb <bz@FreeBSD.org>
AuthorDate: 2025-09-25 12:49:07 +0000
Commit:     Bjoern A. Zeeb <bz@FreeBSD.org>
CommitDate: 2025-10-04 18:28:39 +0000

    pci: add quirk to disable Function-Level Reset (FLR)
    
    MediaTek mt76 WiFi cards are advertising FLR support but after issuing
    a FLR the chipset is gone.  Add a quirk so we can disable FLR.  The
    current reset code will automatically fall back to a power reset.
    
    This makes the card show up under bhyve where before it would just not
    be discovered at all. That should make wifibox work for it and will help
    development for a LinuxKPI based mt76 driver as found in framework laptops
    as no dedicated machine and constant reboots are needed anymore.
    We will likely need to add more PCI vendor/device IDs once we can test
    the other device IDs.
    
    Event:                  EuroBSDCon Devsummit 2025
    After a lot of help from: jhb
    Really implemented by:  jhb (I just typed and tested)
    GH issue:               github.com/pgj/freebsd-wifibox/issues/73
    MFC after:              3 days
    Reviewed by:            imp, emaste
    Differential Revision: https://reviews.freebsd.org/D52728
---
 sys/dev/pci/pci.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c
index 9e43a4c1909f..cde98cb62cef 100644
--- a/sys/dev/pci/pci.c
+++ b/sys/dev/pci/pci.c
@@ -240,6 +240,7 @@ struct pci_quirk {
 #define	PCI_QUIRK_DISABLE_MSIX	5 /* MSI-X doesn't work */
 #define	PCI_QUIRK_MSI_INTX_BUG	6 /* PCIM_CMD_INTxDIS disables MSI */
 #define	PCI_QUIRK_REALLOC_BAR	7 /* Can't allocate memory at the default address */
+#define	PCI_QUIRK_DISABLE_FLR	8 /* Function-Level Reset (FLR) not working. */
 	int	arg1;
 	int	arg2;
 };
@@ -319,6 +320,13 @@ static const struct pci_quirk pci_quirks[] = {
 	 * expected place.
 	 */
 	{ 0x98741002, PCI_QUIRK_REALLOC_BAR,	0, 	0 },
+
+	/*
+	 * With some MediaTek mt76 WiFi FLR does not work despite advertised.
+	 */
+	{ 0x061614c3, PCI_QUIRK_DISABLE_FLR,	0,	0 }, /* mt76 7922 */
+
+	/* end of table */
 	{ 0 }
 };
 
@@ -6740,6 +6748,8 @@ pcie_flr(device_t dev, u_int max_delay, bool force)
 
 	if (!(pci_read_config(dev, cap + PCIER_DEVICE_CAP, 4) & PCIEM_CAP_FLR))
 		return (false);
+	if (pci_has_quirk(pci_get_devid(dev), PCI_QUIRK_DISABLE_FLR))
+		return (false);
 
 	/*
 	 * Disable busmastering to prevent generation of new