[focal:linux-azure][PATCH v2] Revert "video: hyperv_fb: Fix hibernation for the deferred IO feature"

[Marcelo Henrique Cerri]

BugLink: https://bugs.launchpad.net/bugs/1891931

This reverts commit 0a14dbaa0736a6021c02e74d42cf3a7ca5438da6.

This commit was included as part of bug #1880032 ([linux-azure] Enable
Hibernation on The 18.04 and 20.04 5.4 Kernels), however this change
wasn't necessary because the base feature is not present in our 5.4
kernel. The unnecessary commit causes a panic when triggering
hibernation in some azure instances.

The panic can be reproduced in E and D instances types in azure. And
Reverting the commit solves the issue.

After the revert hibernation succeeds on instances under high memory
utilization, up to 70%, when tested with stress-ng (ie, stress-ng --vm
8 --vm-bytes 50% -t 1d).

Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri at canonical.com>
---
 drivers/video/fbdev/hyperv_fb.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
index 5017b4b20781..fe4731f97df7 100644
--- a/drivers/video/fbdev/hyperv_fb.c
+++ b/drivers/video/fbdev/hyperv_fb.c
@@ -891,7 +891,6 @@ static int hvfb_suspend(struct hv_device *hdev)
 	fb_set_suspend(info, 1);
 
 	cancel_delayed_work_sync(&par->dwork);
-	cancel_delayed_work_sync(&info->deferred_work);
 
 	par->update_saved = par->update;
 	par->update = false;
@@ -925,7 +924,6 @@ static int hvfb_resume(struct hv_device *hdev)
 	par->fb_ready = true;
 	par->update = par->update_saved;
 
-	schedule_delayed_work(&info->deferred_work, info->fbdefio->delay);
 	schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
 
 	/* 0 means do resume */
-- 
2.25.1