diff options
| author | rnoland <rnoland@FreeBSD.org> | 2009-03-02 19:00:41 +0000 |
|---|---|---|
| committer | rnoland <rnoland@FreeBSD.org> | 2009-03-02 19:00:41 +0000 |
| commit | dac11360f1f6bc0d720a3b9083fe037c2bcb6d74 (patch) | |
| tree | 34e309d229993a18a27654764c3f79708bdbbf56 | |
| parent | 453adb14fb8994d00a14b341bcf886ca9aad1d9e (diff) | |
| download | FreeBSD-src-dac11360f1f6bc0d720a3b9083fe037c2bcb6d74.zip FreeBSD-src-dac11360f1f6bc0d720a3b9083fe037c2bcb6d74.tar.gz | |
Disable INTx when enabling MSI/MSIX
This addresses interrupt storms that were noticed after enabling MSI
in drm. I think this is due to a loose interpretation of the PCI 2.3
spec, which states that a function using MSI is prohibitted from using
INTx. It appears that some vendors interpretted that to mean that they
should handle it in hardware, while others felt it was the drivers
responsibility.
This fix will also likely resolve interrupt storm related issues with
devices other than drm.
Reviewed by: jhb@
MFC after: 3 days
| -rw-r--r-- | sys/dev/pci/pci.c | 4 | ||||
| -rw-r--r-- | sys/dev/pci/pcireg.h | 1 |
2 files changed, 5 insertions, 0 deletions
diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c index 8f1e51f..c3a6441 100644 --- a/sys/dev/pci/pci.c +++ b/sys/dev/pci/pci.c @@ -2864,6 +2864,8 @@ pci_setup_intr(device_t dev, device_t child, struct resource *irq, int flags, } mte->mte_handlers++; } + /* Disable INTx if we are using MSI/MSIX */ + pci_set_command_bit(dev, child, PCIM_CMD_INTxDIS); bad: if (error) { (void)bus_generic_teardown_intr(dev, child, irq, @@ -2918,6 +2920,8 @@ pci_teardown_intr(device_t dev, device_t child, struct resource *irq, if (mte->mte_handlers == 0) pci_mask_msix(child, rid - 1); } + /* Restore INTx capability for MSI/MSIX */ + pci_clear_command_bit(dev, child, PCIM_CMD_INTxDIS); } error = bus_generic_teardown_intr(dev, child, irq, cookie); if (device_get_parent(child) == dev && rid > 0) diff --git a/sys/dev/pci/pcireg.h b/sys/dev/pci/pcireg.h index 0b83584..04e0f35 100644 --- a/sys/dev/pci/pcireg.h +++ b/sys/dev/pci/pcireg.h @@ -60,6 +60,7 @@ #define PCIM_CMD_PERRESPEN 0x0040 #define PCIM_CMD_SERRESPEN 0x0100 #define PCIM_CMD_BACKTOBACK 0x0200 +#define PCIM_CMD_INTxDIS 0x0400 #define PCIR_STATUS 0x06 #define PCIM_STATUS_CAPPRESENT 0x0010 #define PCIM_STATUS_66CAPABLE 0x0020 |
