drm/nouveau: add support for MSI

Only supported on NV50+ so far, and disabled by default currently.  The
module parameter "msi=1" will enable it.

There's a kernel bug which will cause this to fail if the module (or the
NVIDIA binary driver) has ever been loaded before loading nouveau with
MSI enabled.  As such, this is only safe to enable if you have nouveau
load on boot, and don't wish to ever reload it.

The workaround is to "echo 0 > /sys/bus/pci/devices/<device>/enable"
until the enable count reads 0.  Then you should be able to load nouveau
with MSI enabled.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 3 insertions, 6 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_state.c b/drivers/gpu/drm/nouveau/nouveau_state.c
index f13134aa8c4f..410a79f5e0cd 100644
--- a/drivers/gpu/drm/nouveau/nouveau_state.c
+++ b/drivers/gpu/drm/nouveau/nouveau_state.c
@@ -667,10 +667,7 @@ nouveau_card_init(struct drm_device *dev)
 	if (ret)
 		goto out_fifo;
 
-	/* this call irq_preinstall, register irq handler and
-	 * call irq_postinstall
-	 */
-	ret = drm_irq_install(dev);
+	ret = nouveau_irq_init(dev);
 	if (ret)
 		goto out_display;
 
@@ -701,7 +698,7 @@ nouveau_card_init(struct drm_device *dev)
 out_fence:
 	nouveau_fence_fini(dev);
 out_irq:
-	drm_irq_uninstall(dev);
+	nouveau_irq_fini(dev);
 out_display:
 	engine->display.destroy(dev);
 out_fifo:
@@ -772,7 +769,7 @@ static void nouveau_card_takedown(struct drm_device *dev)
 	nouveau_gpuobj_takedown(dev);
 	nouveau_mem_vram_fini(dev);
 
-	drm_irq_uninstall(dev);
+	nouveau_irq_fini(dev);
 
 	nouveau_pm_fini(dev);
 	nouveau_bios_takedown(dev);