]> git.karo-electronics.de Git - karo-tx-linux.git/commitdiff
virtio-pci: disable msi at startup
authorMichael S. Tsirkin <mst@redhat.com>
Thu, 24 Jun 2010 04:49:06 +0000 (22:49 -0600)
committerGreg Kroah-Hartman <gregkh@suse.de>
Mon, 2 Aug 2010 17:29:16 +0000 (10:29 -0700)
commit b03214d559471359e2a85ae256686381d0672f29 upstream.

virtio-pci resets the device at startup by writing to the status
register, but this does not clear the pci config space,
specifically msi enable status which affects register
layout.

This breaks things like kdump when they try to use e.g. virtio-blk.

Fix by forcing msi off at startup. Since pci.c already has
a routine to do this, we export and use it instead of duplicating code.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: linux-pci@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/pci/pci.c
drivers/virtio/virtio_pci.c

index 37499127c801e5db16927377981e6a721bf0bd0d..8abe98360bfb0db751ee963b1226b9f678715372 100644 (file)
@@ -2294,6 +2294,7 @@ void pci_msi_off(struct pci_dev *dev)
                pci_write_config_word(dev, pos + PCI_MSIX_FLAGS, control);
        }
 }
+EXPORT_SYMBOL_GPL(pci_msi_off);
 
 #ifndef HAVE_ARCH_PCI_SET_DMA_MAX_SEGMENT_SIZE
 int pci_set_dma_max_seg_size(struct pci_dev *dev, unsigned int size)
index 24747aef1952880ca686a1b8d9506acb1e174f55..1e42da2f31896a52cd5be8116689c2327cd269ad 100644 (file)
@@ -636,6 +636,9 @@ static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
        INIT_LIST_HEAD(&vp_dev->virtqueues);
        spin_lock_init(&vp_dev->lock);
 
+       /* Disable MSI/MSIX to bring device to a known good state. */
+       pci_msi_off(pci_dev);
+
        /* enable the device */
        err = pci_enable_device(pci_dev);
        if (err)