video: hyperv_fb: Fix hibernation for the deferred IO feature

fb_deferred_io_work() can access the vmbus ringbuffer by calling
fbdefio->deferred_io() -> synthvid_deferred_io() -> synthvid_update().

Because the vmbus ringbuffer is inaccessible between hvfb_suspend()
and hvfb_resume(), we must cancel info->deferred_work before calling
vmbus_close() and then reschedule it after we reopen the channel
in hvfb_resume().

Fixes: a4ddb11d297e ("video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver")
Fixes: 824946a8b6fb ("video: hyperv_fb: Add the support of hibernation")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Wei Hu <weh@microsoft.com>
Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
index 4cd27e5172a16eb50cb8d38dc57f41236e4f351f..08bc0dfb5ce7d1037e5c5e69540a072229132736 100644 (file)
--- a/drivers/video/fbdev/hyperv_fb.c
+++ b/drivers/video/fbdev/hyperv_fb.c
@@ -1194,6 +1194,7 @@ 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;
@@ -1227,6 +1228,7 @@ 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 */