From: Eric Anholt <eric@anholt.net>
Date: Mon, 16 Jun 2008 22:15:02 +0000 (-0700)
Subject: [intel] Quirk away MSI support on 945G/GM.
X-Git-Tag: submit/1.0/20121108.012404~757^2~46
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e7424e4580159b0ac3e232674dff5c862e851dff;p=profile%2Fivi%2Flibdrm.git

[intel] Quirk away MSI support on 945G/GM.

The PCI caps register reports MSI support even though it isn't really there.
---

diff --git a/linux-core/i915_drv.c b/linux-core/i915_drv.c
index 012ca82..e399f37 100644
--- a/linux-core/i915_drv.c
+++ b/linux-core/i915_drv.c
@@ -628,7 +628,16 @@ static int probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
 	int ret;
 
-	(void) pci_enable_msi(pdev);
+	/* On the 945G/GM, the chipset reports the MSI capability on the
+	 * integrated graphics even though the support isn't actually there
+	 * according to the published specs.  It doesn't appear to function
+	 * correctly in testing on 945G.
+	 * This may be a side effect of MSI having been made available for PEG
+	 * and the registers being closely associated.
+	 */
+	if (pdev->device != 0x2772 && pdev->device != 0x27A2)
+		(void )pci_enable_msi(pdev);
+
 	ret = drm_get_dev(pdev, ent, &driver);
 	if (ret && pdev->msi_enabled)
 		pci_disable_msi(pdev);