[PATCH 2/2] drm/i915: Add dependency on the intel agp module

Andy Whitcroft apw at canonical.com
Wed Apr 7 10:24:20 UTC 2010


From: Zhenyu Wang <zhenyuw at linux.intel.com>

See http://bugzilla.kernel.org/show_bug.cgi?id=15021

Make sure that the appropriate AGP module is loaded and probed before
trying to set up the DRM.  The DRM already depends on the AGP core,
but in this case we know the specific AGP driver we need too, and can
help users avoid the trap of loading the AGP driver after the DRM
driver.

Signed-off-by: Zhenyu Wang <zhenyuw at linux.intel.com>
Signed-off-by: Eric Anholt <eric at anholt.net>

(cherry picked from commit 1f7a6e372e9cb4d749f34c0738d832e6cadb4071 upstream)
BugLink: http://bugs.launchpad.net/bugs/542251

Signed-off-by: Andy Whitcroft <apw at canonical.com>
---
 drivers/char/agp/intel-agp.c    |   10 ++++++++--
 drivers/gpu/drm/i915/i915_drv.c |    6 ++++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/char/agp/intel-agp.c b/drivers/char/agp/intel-agp.c
index 4dcfef0..89f5609 100644
--- a/drivers/char/agp/intel-agp.c
+++ b/drivers/char/agp/intel-agp.c
@@ -10,6 +10,9 @@
 #include <linux/agp_backend.h>
 #include "agp.h"
 
+int intel_agp_enabled;
+EXPORT_SYMBOL(intel_agp_enabled);
+
 /*
  * If we have Intel graphics, we're not going to have anything other than
  * an Intel IOMMU. So make the correct use of the PCI DMA API contingent
@@ -2378,7 +2381,7 @@ static int __devinit agp_intel_probe(struct pci_dev *pdev,
 	struct agp_bridge_data *bridge;
 	u8 cap_ptr = 0;
 	struct resource *r;
-	int i;
+	int i, err;
 
 	cap_ptr = pci_find_capability(pdev, PCI_CAP_ID_AGP);
 
@@ -2466,7 +2469,10 @@ static int __devinit agp_intel_probe(struct pci_dev *pdev,
 				"set gfx device dma mask 36bit failed!\n");
 
 	pci_set_drvdata(pdev, bridge);
-	return agp_add_bridge(bridge);
+	err = agp_add_bridge(bridge);
+	if (!err)
+		intel_agp_enabled = 1;
+	return err;
 }
 
 static void __devexit agp_intel_remove(struct pci_dev *pdev)
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 4746bfe..f7d7c12 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -49,6 +49,7 @@ unsigned int i915_lvds_downclock = 0;
 module_param_named(lvds_downclock, i915_lvds_downclock, int, 0400);
 
 static struct drm_driver driver;
+extern int intel_agp_enabled;
 
 #define INTEL_VGA_DEVICE(id, info) {		\
 	.class = PCI_CLASS_DISPLAY_VGA << 8,	\
@@ -546,6 +547,11 @@ static struct drm_driver driver = {
 
 static int __init i915_init(void)
 {
+	if (!intel_agp_enabled) {
+		DRM_ERROR("drm/i915 can't work without intel_agp module!\n");
+		return -ENODEV;
+	}
+
 	driver.num_ioctls = i915_max_ioctl;
 
 	i915_gem_shrinker_init();
-- 
1.7.0





More information about the kernel-team mailing list