[PATCH 3.12 13/19] hyperv-fb: add pci stub

Greg Kroah-Hartman
2013-11-18T18:40:45Z

From: Gerd Hoffmann <kraxel@redhat.com>

commit 7ad9684721606efbfb9b347346816e1e6baff8bb upstream.

This patch adds a pci stub driver to hyper-fb. The hyperv framebuffer
driver will bind to the pci device then, so linux kernel and userspace
know there is a proper kernel driver for the device active. lspci shows
this for example:

[root@dhcp231 ~]# lspci -vs8
00:08.0 VGA compatible controller: Microsoft Corporation Hyper-V virtual
VGA (prog-if 00 [VGA controller])
Flags: bus master, fast devsel, latency 0, IRQ 11
Memory at f8000000 (32-bit, non-prefetchable) [size=64M]
Expansion ROM at <unassigned> [disabled]
Kernel driver in use: hyperv_fb

Another effect is that the xorg vesa driver will not attach to the
device and thus the Xorg server will automatically use the fbdev
driver instead.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/video/hyperv_fb.c | 40 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 39 insertions(+), 1 deletion(-)

--- a/drivers/video/hyperv_fb.c
+++ b/drivers/video/hyperv_fb.c
@@ -795,12 +795,21 @@ static int hvfb_remove(struct hv_device
}

+static DEFINE_PCI_DEVICE_TABLE(pci_stub_id_table) = {
+ {
+ .vendor = PCI_VENDOR_ID_MICROSOFT,
+ .device = PCI_DEVICE_ID_HYPERV_VIDEO,
+ },
+ { /* end of list */ }
+};
+
static const struct hv_vmbus_device_id id_table[] = {
/* Synthetic Video Device GUID */
{HV_SYNTHVID_GUID},
{}
};

+MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
MODULE_DEVICE_TABLE(vmbus, id_table);

static struct hv_driver hvfb_drv = {
@@ -810,14 +819,43 @@ static struct hv_driver hvfb_drv = {
.remove = hvfb_remove,
};

+static int hvfb_pci_stub_probe(struct pci_dev *pdev,
+ const struct pci_device_id *ent)
+{
+ return 0;
+}
+
+static void hvfb_pci_stub_remove(struct pci_dev *pdev)
+{
+}
+
+static struct pci_driver hvfb_pci_stub_driver = {
+ .name = KBUILD_MODNAME,
+ .id_table = pci_stub_id_table,
+ .probe = hvfb_pci_stub_probe,
+ .remove = hvfb_pci_stub_remove,
+};

static int __init hvfb_drv_init(void)
{
- return vmbus_driver_register(&hvfb_drv);
+ int ret;
+
+ ret = vmbus_driver_register(&hvfb_drv);
+ if (ret != 0)
+ return ret;
+
+ ret = pci_register_driver(&hvfb_pci_stub_driver);
+ if (ret != 0) {
+ vmbus_driver_unregister(&hvfb_drv);
+ return ret;
+ }
+
+ return 0;
}

static void __exit hvfb_drv_exit(void)
{
+ pci_unregister_driver(&hvfb_pci_stub_driver);
vmbus_driver_unregister(&hvfb_drv);
}