Re: [PATCH 3/3] drm/i915: Move the fbdev async_schedule() into intel_fbdev.c

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Sun, Nov 08, 2015 at 05:44:37PM +0100, Lukas Wunner wrote:
> Hi Ville,
> 
> On Fri, Nov 06, 2015 at 03:08:33PM +0200, ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > Reading the driver load/unload code leaves one confused as there's
> > an async_schedule() in the load, but not async_synchronize_full()
> > in sight. In fact it's hidden inside intel_fbdev.c. So let's move the
> > async_schedule() into intel_fbdev.c as well so that it's next to the
> > async_synchronize_full(), which should make the relationship easier
> > to see.
> 
> Hm, what do you think about solving it the other way round, i.e. moving
> the async_synchronize_full() to i915_driver_unload()? Incidentally I was
> working on this same part of the code and that's how I solved it. This way
> it's possible to call intel_fbdev_fini() from intel_fbdev_initial_config().
> With your solution this would deadlock.
> 
> Link: https://github.com/l1k/linux/commit/aa12badac846
> Message-Id: <aa12badac846f24b49d83768146b62e2ac159eb3.1446987413.git.lukas@wunner.de>
> 

I think I'd still like to hide it all in intel_fbdev.c. You could just
split the fbdev_fini() into two parts; one doing the real work, and the
second one just doing async_synchronize + call the first one.

> Thanks,
> 
> Lukas
> 
> 
> > Plus this way we won't schedule a nop function call when fbdev is
> > disabled. And we were passing a pointer to a static inline
> > function to async_schedule(), which seems rather dubious to me.
> > 
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_dma.c    | 3 +--
> >  drivers/gpu/drm/i915/intel_drv.h   | 4 ++--
> >  drivers/gpu/drm/i915/intel_fbdev.c | 7 ++++++-
> >  3 files changed, 9 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> > index c58048f..cae3d78 100644
> > --- a/drivers/gpu/drm/i915/i915_dma.c
> > +++ b/drivers/gpu/drm/i915/i915_dma.c
> > @@ -28,7 +28,6 @@
> >  
> >  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> >  
> > -#include <linux/async.h>
> >  #include <drm/drmP.h>
> >  #include <drm/drm_crtc_helper.h>
> >  #include <drm/drm_fb_helper.h>
> > @@ -437,7 +436,7 @@ static int i915_load_modeset_init(struct drm_device *dev)
> >  	 * scanning against hotplug events. Hence do this first and ignore the
> >  	 * tiny window where we will loose hotplug notifactions.
> >  	 */
> > -	async_schedule(intel_fbdev_initial_config, dev_priv);
> > +	intel_fbdev_initial_config_async(dev);
> >  
> >  	drm_kms_helper_poll_init(dev);
> >  
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index 00d9882..50c78b6 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1298,7 +1298,7 @@ void intel_dvo_init(struct drm_device *dev);
> >  /* legacy fbdev emulation in intel_fbdev.c */
> >  #ifdef CONFIG_DRM_FBDEV_EMULATION
> >  extern int intel_fbdev_init(struct drm_device *dev);
> > -extern void intel_fbdev_initial_config(void *data, async_cookie_t cookie);
> > +extern void intel_fbdev_initial_config_async(struct drm_device *dev);
> >  extern void intel_fbdev_fini(struct drm_device *dev);
> >  extern void intel_fbdev_set_suspend(struct drm_device *dev, int state, bool synchronous);
> >  extern void intel_fbdev_output_poll_changed(struct drm_device *dev);
> > @@ -1309,7 +1309,7 @@ static inline int intel_fbdev_init(struct drm_device *dev)
> >  	return 0;
> >  }
> >  
> > -static inline void intel_fbdev_initial_config(void *data, async_cookie_t cookie)
> > +static inline void intel_fbdev_initial_config_async(struct drm_device *dev)
> >  {
> >  }
> >  
> > diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
> > index 840d6bf..fe1fdb6 100644
> > --- a/drivers/gpu/drm/i915/intel_fbdev.c
> > +++ b/drivers/gpu/drm/i915/intel_fbdev.c
> > @@ -702,7 +702,7 @@ int intel_fbdev_init(struct drm_device *dev)
> >  	return 0;
> >  }
> >  
> > -void intel_fbdev_initial_config(void *data, async_cookie_t cookie)
> > +static void intel_fbdev_initial_config(void *data, async_cookie_t cookie)
> >  {
> >  	struct drm_i915_private *dev_priv = data;
> >  	struct intel_fbdev *ifbdev = dev_priv->fbdev;
> > @@ -711,6 +711,11 @@ void intel_fbdev_initial_config(void *data, async_cookie_t cookie)
> >  	drm_fb_helper_initial_config(&ifbdev->helper, ifbdev->preferred_bpp);
> >  }
> >  
> > +void intel_fbdev_initial_config_async(struct drm_device *dev)
> > +{
> > +	async_schedule(intel_fbdev_initial_config, to_i915(dev));
> > +}
> > +
> >  void intel_fbdev_fini(struct drm_device *dev)
> >  {
> >  	struct drm_i915_private *dev_priv = dev->dev_private;
> > -- 
> > 2.4.10
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ville Syrjälä
Intel OTC
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