[PATCH 4.14 021/115] drm/nouveau/pci: do a msi rearm on init

[Greg Kroah-Hartman]

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Karol Herbst <kherbst@xxxxxxxxxx>


[ Upstream commit a121027d2747168df0aac0c3da35509eea39f61c ]

On my GP107 when I load nouveau after unloading it, for some reason the
GPU stopped sending or the CPU stopped receiving interrupts if MSI was
enabled.

Doing a rearm once before getting any interrupts fixes this.

Signed-off-by: Karol Herbst <kherbst@xxxxxxxxxx>
Reviewed-by: Thierry Reding <treding@xxxxxxxxxx>
Signed-off-by: Ben Skeggs <bskeggs@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/nouveau/nvkm/subdev/pci/base.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/drivers/gpu/drm/nouveau/nvkm/subdev/pci/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/pci/base.c
@@ -136,6 +136,13 @@ nvkm_pci_init(struct nvkm_subdev *subdev
 		return ret;
 
 	pci->irq = pdev->irq;
+
+	/* Ensure MSI interrupts are armed, for the case where there are
+	 * already interrupts pending (for whatever reason) at load time.
+	 */
+	if (pci->msi)
+		pci->func->msi_rearm(pci);
+
 	return ret;
 }