This is a note to let you know that I've just added the patch titled
drm/vmwgfx: Kill some lockdep warnings
to the 4.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-vmwgfx-kill-some-lockdep-warnings.patch
and it can be found in the queue-4.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 93cd16817ae5ddcfc548784b51c76bf6d7923442 Mon Sep 17 00:00:00 2001
From: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
Date: Tue, 3 May 2016 11:24:35 +0200
Subject: drm/vmwgfx: Kill some lockdep warnings
From: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
commit 93cd16817ae5ddcfc548784b51c76bf6d7923442 upstream.
Some global KMS state that is elsewhere protected by the mode_config
mutex here needs to be protected with a local mutex. Remove corresponding
lockdep checks and introduce a new driver-private global_kms_state_mutex,
and make sure its locking order is *after* the crtc locks in order to
avoid having to release those when the new mutex is taken.
Signed-off-by: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
Reviewed-by: Brian Paul <brianp@xxxxxxxxxx>
Reviewed-by: Sinclair Yeh <syeh@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 1 +
drivers/gpu/drm/vmwgfx/vmwgfx_drv.h | 1 +
drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 27 +++++++++++++--------------
drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c | 3 +++
drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c | 3 +++
5 files changed, 21 insertions(+), 14 deletions(-)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -628,6 +628,7 @@ static int vmw_driver_load(struct drm_de
mutex_init(&dev_priv->cmdbuf_mutex);
mutex_init(&dev_priv->release_mutex);
mutex_init(&dev_priv->binding_mutex);
+ mutex_init(&dev_priv->global_kms_state_mutex);
rwlock_init(&dev_priv->resource_lock);
ttm_lock_init(&dev_priv->reservation_sem);
spin_lock_init(&dev_priv->hw_lock);
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -412,6 +412,7 @@ struct vmw_private {
struct drm_property *implicit_placement_property;
unsigned num_implicit;
struct vmw_framebuffer *implicit_fb;
+ struct mutex global_kms_state_mutex;
/*
* Context and surface management.
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -2143,13 +2143,13 @@ int vmw_kms_fbdev_init_data(struct vmw_p
void vmw_kms_del_active(struct vmw_private *dev_priv,
struct vmw_display_unit *du)
{
- lockdep_assert_held_once(&dev_priv->dev->mode_config.mutex);
-
+ mutex_lock(&dev_priv->global_kms_state_mutex);
if (du->active_implicit) {
if (--(dev_priv->num_implicit) == 0)
dev_priv->implicit_fb = NULL;
du->active_implicit = false;
}
+ mutex_unlock(&dev_priv->global_kms_state_mutex);
}
/**
@@ -2165,8 +2165,7 @@ void vmw_kms_add_active(struct vmw_priva
struct vmw_display_unit *du,
struct vmw_framebuffer *vfb)
{
- lockdep_assert_held_once(&dev_priv->dev->mode_config.mutex);
-
+ mutex_lock(&dev_priv->global_kms_state_mutex);
WARN_ON_ONCE(!dev_priv->num_implicit && dev_priv->implicit_fb);
if (!du->active_implicit && du->is_implicit) {
@@ -2174,6 +2173,7 @@ void vmw_kms_add_active(struct vmw_priva
du->active_implicit = true;
dev_priv->num_implicit++;
}
+ mutex_unlock(&dev_priv->global_kms_state_mutex);
}
/**
@@ -2190,16 +2190,13 @@ bool vmw_kms_crtc_flippable(struct vmw_p
struct drm_crtc *crtc)
{
struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
+ bool ret;
- lockdep_assert_held_once(&dev_priv->dev->mode_config.mutex);
-
- if (!du->is_implicit)
- return true;
-
- if (dev_priv->num_implicit != 1)
- return false;
+ mutex_lock(&dev_priv->global_kms_state_mutex);
+ ret = !du->is_implicit || dev_priv->num_implicit == 1;
+ mutex_unlock(&dev_priv->global_kms_state_mutex);
- return true;
+ return ret;
}
/**
@@ -2214,16 +2211,18 @@ void vmw_kms_update_implicit_fb(struct v
struct vmw_display_unit *du = vmw_crtc_to_du(crtc);
struct vmw_framebuffer *vfb;
- lockdep_assert_held_once(&dev_priv->dev->mode_config.mutex);
+ mutex_lock(&dev_priv->global_kms_state_mutex);
if (!du->is_implicit)
- return;
+ goto out_unlock;
vfb = vmw_framebuffer_to_vfb(crtc->primary->fb);
WARN_ON_ONCE(dev_priv->num_implicit != 1 &&
dev_priv->implicit_fb != vfb);
dev_priv->implicit_fb = vfb;
+out_unlock:
+ mutex_unlock(&dev_priv->global_kms_state_mutex);
}
/**
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_scrn.c
@@ -285,14 +285,17 @@ static int vmw_sou_crtc_set_config(struc
}
/* Only one active implicit frame-buffer at a time. */
+ mutex_lock(&dev_priv->global_kms_state_mutex);
if (sou->base.is_implicit &&
dev_priv->implicit_fb && vfb &&
!(dev_priv->num_implicit == 1 &&
sou->base.active_implicit) &&
dev_priv->implicit_fb != vfb) {
+ mutex_unlock(&dev_priv->global_kms_state_mutex);
DRM_ERROR("Multiple implicit framebuffers not supported.\n");
return -EINVAL;
}
+ mutex_unlock(&dev_priv->global_kms_state_mutex);
/* since they always map one to one these are safe */
connector = &sou->base.connector;
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
@@ -553,12 +553,15 @@ static int vmw_stdu_crtc_set_config(stru
}
/* Only one active implicit frame-buffer at a time. */
+ mutex_lock(&dev_priv->global_kms_state_mutex);
if (!turning_off && stdu->base.is_implicit && dev_priv->implicit_fb &&
!(dev_priv->num_implicit == 1 && stdu->base.active_implicit)
&& dev_priv->implicit_fb != vfb) {
+ mutex_unlock(&dev_priv->global_kms_state_mutex);
DRM_ERROR("Multiple implicit framebuffers not supported.\n");
return -EINVAL;
}
+ mutex_unlock(&dev_priv->global_kms_state_mutex);
/* Since they always map one to one these are safe */
connector = &stdu->base.connector;
Patches currently in stable-queue which might be from thellstrom@xxxxxxxxxx are
queue-4.6/drm-vmwgfx-kill-some-lockdep-warnings.patch
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