diff options
author | Thomas Hellstrom <thellstrom@vmware.com> | 2015-09-08 09:11:10 +0200 |
---|---|---|
committer | Thomas Hellstrom <thellstrom@vmware.com> | 2015-09-08 09:05:25 -0700 |
commit | 2857a3d1ac235e2b1e1b912abac0c37064b69ef5 (patch) | |
tree | b512a3c995c31672c243a49efd49c8b7dfdd9f19 | |
parent | be5a1df590733f54a649ce88533ccf2c11796ff0 (diff) |
vmwgfx: Fix a circular locking dependency in the fbdev code
When a user-space process writes directly to the fbdev framebuffer,
we hit a circular locking dependency. Fix this by introducing a local
delayed work callback so that the defio lock can be released before
calling into the modesetting code for a dirty update.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
-rw-r--r-- | vmwgfx_fb.c | 39 |
1 files changed, 22 insertions, 17 deletions
diff --git a/vmwgfx_fb.c b/vmwgfx_fb.c index 74f8ce1..f2b7a85 100644 --- a/vmwgfx_fb.c +++ b/vmwgfx_fb.c @@ -72,8 +72,7 @@ struct vmw_fb_par { struct drm_crtc *crtc; struct drm_connector *con; - - bool local_mode; + struct delayed_work local_work; }; static int vmw_fb_setcolreg(unsigned regno, unsigned red, unsigned green, @@ -172,8 +171,10 @@ static int vmw_fb_blank(int blank, struct fb_info *info) * Dirty code */ -static void vmw_fb_dirty_flush(struct vmw_fb_par *par) +static void vmw_fb_dirty_flush(struct work_struct *work) { + struct vmw_fb_par *par = container_of(work, struct vmw_fb_par, + local_work.work); struct vmw_private *vmw_priv = par->vmw_priv; struct fb_info *info = vmw_priv->fb_info; unsigned long irq_flags; @@ -255,7 +256,6 @@ static void vmw_fb_dirty_mark(struct vmw_fb_par *par, unsigned x1, unsigned y1, unsigned width, unsigned height) { - struct fb_info *info = par->vmw_priv->fb_info; unsigned long flags; unsigned x2 = x1 + width; unsigned y2 = y1 + height; @@ -272,11 +272,8 @@ static void vmw_fb_dirty_mark(struct vmw_fb_par *par, /* if we are active start the dirty work * we share the work with the defio system */ if (par->dirty.active) -#if (defined(VMWGFX_STANDALONE) && defined(VMWGFX_FB_DEFERRED)) - schedule_delayed_work(&par->def_par.deferred_work, VMW_DIRTY_DELAY); -#else - schedule_delayed_work(&info->deferred_work, VMW_DIRTY_DELAY); -#endif + schedule_delayed_work(&par->local_work, + VMW_DIRTY_DELAY); } else { if (x1 < par->dirty.x1) par->dirty.x1 = x1; @@ -350,9 +347,14 @@ static void vmw_deferred_io(struct fb_info *info, par->dirty.x2 = info->var.xres; par->dirty.y2 = y2; spin_unlock_irqrestore(&par->dirty.lock, flags); - } - vmw_fb_dirty_flush(par); + /* + * Since we've already waited on this work once, try to + * execute asap. + */ + cancel_delayed_work(&par->local_work); + schedule_delayed_work(&par->local_work, 0); + } }; #if (defined(VMWGFX_STANDALONE) && defined(VMWGFX_FB_DEFERRED)) @@ -631,11 +633,7 @@ static int vmw_fb_set_par(struct fb_info *info) /* If there already was stuff dirty we wont * schedule a new work, so lets do it now */ -#if (defined(VMWGFX_STANDALONE) && defined(VMWGFX_FB_DEFERRED)) - schedule_delayed_work(&par->def_par.deferred_work, 0); -#else - schedule_delayed_work(&info->deferred_work, 0); -#endif + schedule_delayed_work(&par->local_work, 0); out_unlock: if (old_mode) @@ -692,6 +690,7 @@ int vmw_fb_init(struct vmw_private *vmw_priv) vmw_priv->fb_info = info; par = info->par; memset(par, 0, sizeof(*par)); + INIT_DELAYED_WORK(&par->local_work, &vmw_fb_dirty_flush); par->vmw_priv = vmw_priv; par->vmalloc = NULL; par->max_width = fb_width; @@ -838,6 +837,7 @@ int vmw_fb_close(struct vmw_private *vmw_priv) /* ??? order */ fb_deferred_io_cleanup(info); + cancel_delayed_work_sync(&par->local_work); unregister_framebuffer(info); (void) vmw_fb_kms_detach(par, true, true); @@ -864,7 +864,12 @@ int vmw_fb_off(struct vmw_private *vmw_priv) par->dirty.active = false; spin_unlock_irqrestore(&par->dirty.lock, flags); - flush_scheduled_work(); +#if (defined(VMWGFX_STANDALONE) && defined(VMWGFX_FB_DEFERRED)) + flush_delayed_work(&par->def_par.deferred_work); +#else + flush_delayed_work(&info->deferred_work); +#endif + flush_delayed_work(&par->local_work); mutex_lock(&par->bo_mutex); (void) vmw_fb_kms_detach(par, true, false); |