drm/nouveau/pci/msi: disable MSI on big-endian platforms by default

imirkin · gregkh · commit 966e3a2d98c1 · 2017-09-13T14:09:45.000-07:00
commit bc60c90f472b6e762ea96ef384072145adc8d4af upstream.

It appears that MSI does not work on either G5 PPC nor on a E5500-based
platform, where other hardware is reported to work fine with MSI.

Both tests were conducted with NV4x hardware, so perhaps other (or even
this) hardware can be made to work. It's still possible to force-enable
with config=NvMSI=1 on load.

Signed-off-by: Ilia Mirkin &lt;imirkin@alum.mit.edu&gt;
Signed-off-by: Ben Skeggs &lt;bskeggs@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/pci/base.c b/drivers/gpu/drm/nouveau/nvkm/subdev/pci/base.c
@@ -180,6 +180,10 @@ nvkm_pci_new_(const struct nvkm_pci_func *func, struct nvkm_device *device,
 		}
 	}
 
+#ifdef __BIG_ENDIAN
+	pci->msi = false;
+#endif
+
 	pci->msi = nvkm_boolopt(device->cfgopt, "NvMSI", pci->msi);
 	if (pci->msi && func->msi_rearm) {
 		pci->msi = pci_enable_msi(pci->pdev) == 0;

Original file line number	Diff line number	Diff line change
`@@ -180,6 +180,10 @@ nvkm_pci_new_(const struct nvkm_pci_func func, struct nvkm_device device,`
`180`	`180`	`}`
`181`	`181`	`}`
`182`	`182`
	`183`	`+#ifdef __BIG_ENDIAN`
	`184`	`+ pci->msi = false;`
	`185`	`+#endif`
	`186`	`+`
`183`	`187`	`pci->msi = nvkm_boolopt(device->cfgopt, "NvMSI", pci->msi);`
`184`	`188`	`if (pci->msi && func->msi_rearm) {`
`185`	`189`	`pci->msi = pci_enable_msi(pci->pdev) == 0;`