[PATCH] drm/radeon: Bail earlier when radeon.cik_/si_support=0 is passed

[Hans de Goede]

Bail from the pci_driver probe function instead of from the drm_driver
load function.

This avoid /dev/dri/card0 temporarily getting registered and then
unregistered again, sending unwanted add / remove udev events to
userspace.

Specifically this avoids triggering the (userspace) bug fixed by this
plymouth merge-request:
https://gitlab.freedesktop.org/plymouth/plymouth/merge_requests/59

Note that despite that being an userspace bug, not sending unnecessary
udev events is a good idea in general.

BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1490490
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
 drivers/gpu/drm/radeon/radeon_drv.c | 31 +++++++++++++++++++++++++++++
 drivers/gpu/drm/radeon/radeon_kms.c | 25 -----------------------
 2 files changed, 31 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
index a6cbe11f79c6..7033f3a38c87 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -325,8 +325,39 @@ bool radeon_device_is_virtual(void);
 static int radeon_pci_probe(struct pci_dev *pdev,
 			    const struct pci_device_id *ent)
 {
+	unsigned long flags = 0;
 	int ret;
 
+	if (!ent)
+		return -ENODEV; /* Avoid NULL-ptr deref in drm_get_pci_dev */
+
+	flags = ent->driver_data;
+
+	if (!radeon_si_support) {
+		switch (flags & RADEON_FAMILY_MASK) {
+		case CHIP_TAHITI:
+		case CHIP_PITCAIRN:
+		case CHIP_VERDE:
+		case CHIP_OLAND:
+		case CHIP_HAINAN:
+			dev_info(&pdev->dev,
+				 "SI support disabled by module param\n");
+			return -ENODEV;
+		}
+	}
+	if (!radeon_cik_support) {
+		switch (flags & RADEON_FAMILY_MASK) {
+		case CHIP_KAVERI:
+		case CHIP_BONAIRE:
+		case CHIP_HAWAII:
+		case CHIP_KABINI:
+		case CHIP_MULLINS:
+			dev_info(&pdev->dev,
+				 "CIK support disabled by module param\n");
+			return -ENODEV;
+		}
+	}
+
 	if (vga_switcheroo_client_probe_defer(pdev))
 		return -EPROBE_DEFER;
 
diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
index 07f7ace42c4b..e85c554eeaa9 100644
--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -100,31 +100,6 @@ int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags)
 	struct radeon_device *rdev;
 	int r, acpi_status;
 
-	if (!radeon_si_support) {
-		switch (flags & RADEON_FAMILY_MASK) {
-		case CHIP_TAHITI:
-		case CHIP_PITCAIRN:
-		case CHIP_VERDE:
-		case CHIP_OLAND:
-		case CHIP_HAINAN:
-			dev_info(dev->dev,
-				 "SI support disabled by module param\n");
-			return -ENODEV;
-		}
-	}
-	if (!radeon_cik_support) {
-		switch (flags & RADEON_FAMILY_MASK) {
-		case CHIP_KAVERI:
-		case CHIP_BONAIRE:
-		case CHIP_HAWAII:
-		case CHIP_KABINI:
-		case CHIP_MULLINS:
-			dev_info(dev->dev,
-				 "CIK support disabled by module param\n");
-			return -ENODEV;
-		}
-	}
-
 	rdev = kzalloc(sizeof(struct radeon_device), GFP_KERNEL);
 	if (rdev == NULL) {
 		return -ENOMEM;
-- 
2.23.0