[SRU][Kinetic][PATCH 1/1] UBUNTU: SAUCE: Revert "video/aperture: Disable and unregister sysfb devices via aperture helpers"

[Matthew Ruffell]

BugLink: https://bugs.launchpad.net/bugs/2007001

This reverts commit 89314ff239e1933357419fa91b20190150f114a8 (ubuntu-kinetic).

Numerous VMWare users have reported that vmwgfx cannot reserve the memory
region for the graphics framebuffer, leading their VMs to have blank screens.

They see the following in dmesg:

[ 11.135360] vmwgfx 0000:00:0f.0: BAR 2: can't reserve [mem 0x70000000-0x77ffffff 64bit pref]
[ 11.135366] vmwgfx: probe of 0000:00:0f.0 failed with error -16

And a cat /proc/iomem shows this:

50000000-7fffffff : PCI Bus 0000:00
  70000000-77ffffff : 0000:00:0f.0
    70000000-702fffff : BOOTFB

The kernel has failed to release this memory region for vmwgfx to occupy.

"video/aperture: Disable and unregister sysfb devices via aperture helpers" is
a part of a much larger series that refactors device ownership, and this commit
requires the whole series to be applied to work correctly. The whole series is
large, has numerous fixups, and is not suitable for a stable kernel in the first
place, as it does not fix any specific issue.

Hence, reverting is the best way to fix this.

Signed-off-by: Matthew Ruffell <matthew.ruffell at canonical.com>
---
 drivers/gpu/drm/drm_aperture.c   | 14 --------------
 drivers/video/fbdev/core/fbmem.c | 12 ++++++++++++
 2 files changed, 12 insertions(+), 14 deletions(-)

diff --git a/drivers/gpu/drm/drm_aperture.c b/drivers/gpu/drm/drm_aperture.c
index 528e2544661c..059fd71424f6 100644
--- a/drivers/gpu/drm/drm_aperture.c
+++ b/drivers/gpu/drm/drm_aperture.c
@@ -7,7 +7,6 @@
 #include <linux/pci.h>
 #include <linux/platform_device.h> /* for firmware helpers */
 #include <linux/slab.h>
-#include <linux/sysfb.h>
 #include <linux/types.h>
 #include <linux/vgaarb.h>
 
@@ -293,20 +292,7 @@ int drm_aperture_remove_conflicting_framebuffers(resource_size_t base, resource_
 #if IS_REACHABLE(CONFIG_FB)
 	struct apertures_struct *a;
 	int ret;
-#endif
-
-	/*
-	 * If a driver asked to unregister a platform device registered by
-	 * sysfb, then can be assumed that this is a driver for a display
-	 * that is set up by the system firmware and has a generic driver.
-	 *
-	 * Drivers for devices that don't have a generic driver will never
-	 * ask for this, so let's assume that a real driver for the display
-	 * was already probed and prevent sysfb to register devices later.
-	 */
-	sysfb_disable();
 
-#if IS_REACHABLE(CONFIG_FB)
 	a = alloc_apertures(1);
 	if (!a)
 		return -ENOMEM;
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 959fa1948f29..bc5a9154783d 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -19,6 +19,7 @@
 #include <linux/kernel.h>
 #include <linux/major.h>
 #include <linux/slab.h>
+#include <linux/sysfb.h>
 #include <linux/mm.h>
 #include <linux/mman.h>
 #include <linux/vt.h>
@@ -1768,6 +1769,17 @@ int remove_conflicting_framebuffers(struct apertures_struct *a,
 		do_free = true;
 	}
 
+	/*
+	 * If a driver asked to unregister a platform device registered by
+	 * sysfb, then can be assumed that this is a driver for a display
+	 * that is set up by the system firmware and has a generic driver.
+	 *
+	 * Drivers for devices that don't have a generic driver will never
+	 * ask for this, so let's assume that a real driver for the display
+	 * was already probed and prevent sysfb to register devices later.
+	 */
+	sysfb_disable();
+
 	mutex_lock(&registration_lock);
 	do_remove_conflicting_framebuffers(a, name, primary);
 	mutex_unlock(&registration_lock);
-- 
2.39.2