Re: [PATCH v2 02/13] drm/vmwgfx: Stop using plane->fb in vmw_kms_helper_dirty()

[Ville Syrjälä]

On Mon, Jun 04, 2018 at 11:13:53AM -0700, Sinclair Yeh wrote:
> On Wed, May 30, 2018 at 11:08:57PM +0300, Ville Syrjälä wrote:
> > On Fri, May 25, 2018 at 09:50:34PM +0300, Ville Syrjala wrote:
> > > From: Ville Syrjälä 
> > > 
> > > Instead of plane->fb (which we're going to deprecate for atomic drivers)
> > > we need to look at plane->state->fb. The maze of code leading to
> > > vmw_kms_helper_dirty() wasn't particularly clear, but my analysis
> > > concluded that the calls originating from 
> > > vmw_*_primary_plane_atomic_update()
> > > all pass in the crtc which means we'll never end up in this branch
> > > of the function. All other callers use drm_modeset_lock_all() somewhere
> > > higher up, which means accessing plane->state is safe. We'll toss in
> > > a lockdep assert to catch wrongdoers.
> > > 
> > > v2: Drop the comment and make the code do what it did before (Thomas)
> > > 
> > > Cc: Deepak Rawat 
> > > Cc: Thomas Hellstrom 
> > > Cc: Sinclair Yeh 
> > > Cc: VMware Graphics 
> > > Cc: Daniel Vetter 
> > > Signed-off-by: Ville Syrjälä 
> > > ---
> > >  drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 9 ++---
> > >  1 file changed, 6 insertions(+), 3 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c 
> > > b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> > > index 2e4c38bb846d..5417eb1b486e 100644
> > > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> > > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> > > @@ -2326,9 +2326,12 @@ int vmw_kms_helper_dirty(struct vmw_private 
> > > *dev_priv,
> > >   } else {
> > >   list_for_each_entry(crtc, _priv->dev->mode_config.crtc_list,
> > >   head) {
> > > - if (crtc->primary->fb != >base)
> > > - continue;
> > > - units[num_units++] = vmw_crtc_to_du(crtc);
> > > + struct drm_plane *plane = crtc->primary;
> > > +
> > > + lockdep_assert_held(>mutex);
> > 
> > kbuild test robot told me
> > >> include/linux/lockdep.h:347:52: error: 'struct drm_modeset_lock' has
> > >> no member named 'dep_map'  
> > #define lockdep_is_held(lock)  lock_is_held(&(lock)->dep_map)   
> >
> > 
> > Maybe I'll just drop the asserts? Or do people really want them
> > (in which case I gues I need to dig out the underlying mutex)?
> 
> Eitherway is fine with me.

I just dropped them, and pushe the series to drm-misc-next. Thanks for
the reviews everyone.

Fingers crossed that no new uses of the legacy pointers have been added
in the meantime. A quick grep didn't seem to catch anything at least,
but selective blindness can occur sometimes. So just holler if
anything broke...

-- 
Ville Syrjälä
Intel
___
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH v2 02/13] drm/vmwgfx: Stop using plane->fb in vmw_kms_helper_dirty()

[Sinclair Yeh]

On Wed, May 30, 2018 at 11:08:57PM +0300, Ville Syrjälä wrote:
> On Fri, May 25, 2018 at 09:50:34PM +0300, Ville Syrjala wrote:
> > From: Ville Syrjälä 
> > 
> > Instead of plane->fb (which we're going to deprecate for atomic drivers)
> > we need to look at plane->state->fb. The maze of code leading to
> > vmw_kms_helper_dirty() wasn't particularly clear, but my analysis
> > concluded that the calls originating from 
> > vmw_*_primary_plane_atomic_update()
> > all pass in the crtc which means we'll never end up in this branch
> > of the function. All other callers use drm_modeset_lock_all() somewhere
> > higher up, which means accessing plane->state is safe. We'll toss in
> > a lockdep assert to catch wrongdoers.
> > 
> > v2: Drop the comment and make the code do what it did before (Thomas)
> > 
> > Cc: Deepak Rawat 
> > Cc: Thomas Hellstrom 
> > Cc: Sinclair Yeh 
> > Cc: VMware Graphics 
> > Cc: Daniel Vetter 
> > Signed-off-by: Ville Syrjälä 
> > ---
> >  drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 9 ++---
> >  1 file changed, 6 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c 
> > b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> > index 2e4c38bb846d..5417eb1b486e 100644
> > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> > @@ -2326,9 +2326,12 @@ int vmw_kms_helper_dirty(struct vmw_private 
> > *dev_priv,
> > } else {
> > list_for_each_entry(crtc, _priv->dev->mode_config.crtc_list,
> > head) {
> > -   if (crtc->primary->fb != >base)
> > -   continue;
> > -   units[num_units++] = vmw_crtc_to_du(crtc);
> > +   struct drm_plane *plane = crtc->primary;
> > +
> > +   lockdep_assert_held(>mutex);
> 
> kbuild test robot told me
> >> include/linux/lockdep.h:347:52: error: 'struct drm_modeset_lock' has
> >> no member named 'dep_map'  
> #define lockdep_is_held(lock)  lock_is_held(&(lock)->dep_map) 
>  
> 
> Maybe I'll just drop the asserts? Or do people really want them
> (in which case I gues I need to dig out the underlying mutex)?

Eitherway is fine with me.


> 
> > +
> > +   if (plane->state->fb == >base)
> > +   units[num_units++] = vmw_crtc_to_du(crtc);
> > }
> > }
> >  
> > -- 
> > 2.16.1
> 
> -- 
> Ville Syrjälä
> Intel
___
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Re: [PATCH v2 02/13] drm/vmwgfx: Stop using plane->fb in vmw_kms_helper_dirty()

[Ville Syrjälä]

On Fri, May 25, 2018 at 09:50:34PM +0300, Ville Syrjala wrote:
> From: Ville Syrjälä 
> 
> Instead of plane->fb (which we're going to deprecate for atomic drivers)
> we need to look at plane->state->fb. The maze of code leading to
> vmw_kms_helper_dirty() wasn't particularly clear, but my analysis
> concluded that the calls originating from vmw_*_primary_plane_atomic_update()
> all pass in the crtc which means we'll never end up in this branch
> of the function. All other callers use drm_modeset_lock_all() somewhere
> higher up, which means accessing plane->state is safe. We'll toss in
> a lockdep assert to catch wrongdoers.
> 
> v2: Drop the comment and make the code do what it did before (Thomas)
> 
> Cc: Deepak Rawat 
> Cc: Thomas Hellstrom 
> Cc: Sinclair Yeh 
> Cc: VMware Graphics 
> Cc: Daniel Vetter 
> Signed-off-by: Ville Syrjälä 
> ---
>  drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 9 ++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c 
> b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> index 2e4c38bb846d..5417eb1b486e 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> @@ -2326,9 +2326,12 @@ int vmw_kms_helper_dirty(struct vmw_private *dev_priv,
>   } else {
>   list_for_each_entry(crtc, _priv->dev->mode_config.crtc_list,
>   head) {
> - if (crtc->primary->fb != >base)
> - continue;
> - units[num_units++] = vmw_crtc_to_du(crtc);
> + struct drm_plane *plane = crtc->primary;
> +
> + lockdep_assert_held(>mutex);

kbuild test robot told me
>> include/linux/lockdep.h:347:52: error: 'struct drm_modeset_lock' has
>> no member named 'dep_map'  
#define lockdep_is_held(lock)  lock_is_held(&(lock)->dep_map)   
   

Maybe I'll just drop the asserts? Or do people really want them
(in which case I gues I need to dig out the underlying mutex)?

> +
> + if (plane->state->fb == >base)
> + units[num_units++] = vmw_crtc_to_du(crtc);
>   }
>   }
>  
> -- 
> 2.16.1

-- 
Ville Syrjälä
Intel
___
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

[PATCH v2 02/13] drm/vmwgfx: Stop using plane->fb in vmw_kms_helper_dirty()

[Ville Syrjala]

From: Ville Syrjälä 

Instead of plane->fb (which we're going to deprecate for atomic drivers)
we need to look at plane->state->fb. The maze of code leading to
vmw_kms_helper_dirty() wasn't particularly clear, but my analysis
concluded that the calls originating from vmw_*_primary_plane_atomic_update()
all pass in the crtc which means we'll never end up in this branch
of the function. All other callers use drm_modeset_lock_all() somewhere
higher up, which means accessing plane->state is safe. We'll toss in
a lockdep assert to catch wrongdoers.

v2: Drop the comment and make the code do what it did before (Thomas)

Cc: Deepak Rawat 
Cc: Thomas Hellstrom 
Cc: Sinclair Yeh 
Cc: VMware Graphics 
Cc: Daniel Vetter 
Signed-off-by: Ville Syrjälä 
---
 drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 9 ++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c 
b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index 2e4c38bb846d..5417eb1b486e 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -2326,9 +2326,12 @@ int vmw_kms_helper_dirty(struct vmw_private *dev_priv,
} else {
list_for_each_entry(crtc, _priv->dev->mode_config.crtc_list,
head) {
-   if (crtc->primary->fb != >base)
-   continue;
-   units[num_units++] = vmw_crtc_to_du(crtc);
+   struct drm_plane *plane = crtc->primary;
+
+   lockdep_assert_held(>mutex);
+
+   if (plane->state->fb == >base)
+   units[num_units++] = vmw_crtc_to_du(crtc);
}
}
 
-- 
2.16.1

___
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel