2019-11-20 07:16:18

by Dexuan Cui

[permalink] [raw]
Subject: [PATCH] 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 <[email protected]>
---

This patch fixes the 2 aforementioned patches on Sasha Levin's Hyper-V tree's
hyperv-next branch:
https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git/log/?h=hyperv-next

The 2 aforementioned patches have not appeared in the mainline yet, so
please pick up this patch onto he same hyperv-next branch.

drivers/video/fbdev/hyperv_fb.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
index 4cd27e5172a1..08bc0dfb5ce7 100644
--- 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 */
--
2.19.1



2019-11-21 02:49:02

by Wei Hu

[permalink] [raw]
Subject: RE: [PATCH] video: hyperv_fb: Fix hibernation for the deferred IO feature

> -----Original Message-----
> From: Dexuan Cui <[email protected]>
> Sent: Wednesday, November 20, 2019 3:14 PM
> To: KY Srinivasan <[email protected]>; Haiyang Zhang
> <[email protected]>; Stephen Hemminger <[email protected]>;
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; linux-
> [email protected]; Michael Kelley <[email protected]>; Sasha Levin
> <[email protected]>
> Cc: Wei Hu <[email protected]>; Dexuan Cui <[email protected]>
> Subject: [PATCH] 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 <[email protected]>
> ---
>
> This patch fixes the 2 aforementioned patches on Sasha Levin's Hyper-V tree's
> hyperv-next branch:
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kern
> el.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Fhyperv%2Flinux.git%2Flog
> %2F%3Fh%3Dhyperv-
> next&amp;data=02%7C01%7Cweh%40microsoft.com%7C451143ff78f04401d9
> 6f08d76d893a84%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637
> 098308493217121&amp;sdata=P2fo%2F1TJUMIj5FtJCOp2QwDrghhVfPSCEJ4f1
> vkOXvI%3D&amp;reserved=0
>
> The 2 aforementioned patches have not appeared in the mainline yet, so please
> pick up this patch onto he same hyperv-next branch.
>
> drivers/video/fbdev/hyperv_fb.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
> index 4cd27e5172a1..08bc0dfb5ce7 100644
> --- 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 */
> --
> 2.19.1

Signed-off-by: Wei Hu <[email protected]>

2019-11-21 06:09:18

by Wei Hu

[permalink] [raw]
Subject: RE: [PATCH] video: hyperv_fb: Fix hibernation for the deferred IO feature


> -----Original Message-----
> From: Wei Hu
> Sent: 2019??11??21?? 10:47
> To: Dexuan Cui <[email protected]>; KY Srinivasan <[email protected]>;
> Haiyang Zhang <[email protected]>; Stephen Hemminger
> <[email protected]>; [email protected]; [email protected];
> [email protected]; [email protected]; linux-
> [email protected]; [email protected]; Michael Kelley
> <[email protected]>; Sasha Levin <[email protected]>
> Subject: RE: [PATCH] video: hyperv_fb: Fix hibernation for the deferred IO
> feature
>
> > -----Original Message-----
> > From: Dexuan Cui <[email protected]>
> > Sent: Wednesday, November 20, 2019 3:14 PM
> > To: KY Srinivasan <[email protected]>; Haiyang Zhang
> > <[email protected]>; Stephen Hemminger
> <[email protected]>;
> > [email protected]; [email protected]; [email protected];
> > [email protected]; [email protected]; linux-
> > [email protected]; Michael Kelley <[email protected]>; Sasha
> Levin
> > <[email protected]>
> > Cc: Wei Hu <[email protected]>; Dexuan Cui <[email protected]>
> > Subject: [PATCH] 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 <[email protected]>
> > ---
> >
> > This patch fixes the 2 aforementioned patches on Sasha Levin's Hyper-V tree's
> > hyperv-next branch:
> >
> https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgit.kern
> > el.org%2Fpub%2Fscm%2Flinux%2Fkernel%2Fgit%2Fhyperv%2Flinux.git%2Flog
> > %2F%3Fh%3Dhyperv-
> >
> next&amp;data=02%7C01%7Cweh%40microsoft.com%7C451143ff78f04401d9
> > 6f08d76d893a84%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C637
> >
> 098308493217121&amp;sdata=P2fo%2F1TJUMIj5FtJCOp2QwDrghhVfPSCEJ4f1
> > vkOXvI%3D&amp;reserved=0
> >
> > The 2 aforementioned patches have not appeared in the mainline yet, so
> please
> > pick up this patch onto he same hyperv-next branch.
> >
> > drivers/video/fbdev/hyperv_fb.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
> > index 4cd27e5172a1..08bc0dfb5ce7 100644
> > --- 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 */
> > --
> > 2.19.1
>
> Signed-off-by: Wei Hu <[email protected]>

Sorry, please disregard the Signed-off-by line I added above. It was my mistake.
should be:

Reviewed-by: Wei Hu <[email protected]>