[Intel-gfx] [PATCH] drm/i915: Localise the fbdev console lock frobbing
Daniel Vetter
daniel at ffwll.ch
Wed Aug 13 13:26:40 CEST 2014
On Tue, Aug 12, 2014 at 03:15:17PM +0100, Chris Wilson wrote:
> Rather than take and release the console_lock() around a non-existent
> DRM_I915_FBDEV, move the lock acquisation into the callee where it will
> be compiled out by the config option entirely. This includes moving the
> deferred fb_set_suspend() dance and encapsulating it entirely within
> intel_fbdev.c.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
> drivers/gpu/drm/i915/i915_dma.c | 5 ++---
> drivers/gpu/drm/i915/i915_drv.c | 26 +-------------------------
> drivers/gpu/drm/i915/i915_drv.h | 8 --------
> drivers/gpu/drm/i915/intel_fbdev.c | 33 +++++++++++++++++++++++++++++++++
> 4 files changed, 36 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> index 49149406fcd8..d0b3411fc13c 100644
> --- a/drivers/gpu/drm/i915/i915_dma.c
> +++ b/drivers/gpu/drm/i915/i915_dma.c
> @@ -1339,8 +1339,6 @@ static int i915_load_modeset_init(struct drm_device *dev)
> if (ret)
> goto cleanup_irq;
>
> - INIT_WORK(&dev_priv->console_resume_work, intel_console_resume);
> -
> intel_modeset_gem_init(dev);
>
> /* Always safe in the mode setting case. */
> @@ -1835,6 +1833,8 @@ int i915_driver_unload(struct drm_device *dev)
> return ret;
> }
>
> + flush_scheduled_work();
Tbh I prefer the explicit work flushing and keeping it in dev_priv. We can
shovel it into the I915_FBDEV #ifdef that's already there though.
> +
> i915_perf_unregister(dev);
> intel_fini_runtime_pm(dev_priv);
>
> @@ -1859,7 +1859,6 @@ int i915_driver_unload(struct drm_device *dev)
> if (drm_core_check_feature(dev, DRIVER_MODESET)) {
> intel_fbdev_fini(dev);
> intel_modeset_cleanup(dev);
> - cancel_work_sync(&dev_priv->console_resume_work);
>
> /*
> * free the memory space allocated for the child device
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 35b119072c11..9adafc7c5819 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -558,9 +558,7 @@ static int i915_drm_freeze(struct drm_device *dev)
> intel_uncore_forcewake_reset(dev, false);
> intel_opregion_fini(dev);
>
> - console_lock();
> intel_fbdev_set_suspend(dev, FBINFO_STATE_SUSPENDED);
This one here must be synchronous.
> - console_unlock();
>
> dev_priv->suspend_count++;
>
> @@ -599,18 +597,6 @@ int i915_suspend(struct drm_device *dev, pm_message_t state)
> return 0;
> }
>
> -void intel_console_resume(struct work_struct *work)
> -{
> - struct drm_i915_private *dev_priv =
> - container_of(work, struct drm_i915_private,
> - console_resume_work);
> - struct drm_device *dev = dev_priv->dev;
> -
> - console_lock();
> - intel_fbdev_set_suspend(dev, FBINFO_STATE_RUNNING);
> - console_unlock();
> -}
> -
> static int i915_drm_thaw_early(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -683,17 +669,7 @@ static int __i915_drm_thaw(struct drm_device *dev, bool restore_gtt_mappings)
>
> intel_opregion_init(dev);
>
> - /*
> - * The console lock can be pretty contented on resume due
> - * to all the printk activity. Try to keep it out of the hot
> - * path of resume if possible.
> - */
> - if (console_trylock()) {
> - intel_fbdev_set_suspend(dev, FBINFO_STATE_RUNNING);
> - console_unlock();
> - } else {
> - schedule_work(&dev_priv->console_resume_work);
> - }
> + intel_fbdev_set_suspend(dev, FBINFO_STATE_RUNNING);
>
> mutex_lock(&dev_priv->modeset_restore_lock);
> dev_priv->modeset_restore = MODESET_DONE;
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 517a78e27bbb..e38dd39d84ad 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1603,12 +1603,6 @@ struct drm_i915_private {
> struct intel_fbdev *fbdev;
> #endif
>
> - /*
> - * The console may be contended at resume, but we don't
> - * want it to block on it.
> - */
> - struct work_struct console_resume_work;
> -
> struct drm_property *broadcast_rgb_property;
> struct drm_property *force_audio_property;
>
> @@ -2310,8 +2304,6 @@ extern unsigned long i915_gfx_val(struct drm_i915_private *dev_priv);
> extern void i915_update_gfx_val(struct drm_i915_private *dev_priv);
> int vlv_force_gfx_clock(struct drm_i915_private *dev_priv, bool on);
>
> -extern void intel_console_resume(struct work_struct *work);
> -
> /* i915_irq.c */
> void i915_queue_hangcheck(struct drm_device *dev);
> __printf(3, 4)
> diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
> index 5d879d185fe1..4eecb34a0e32 100644
> --- a/drivers/gpu/drm/i915/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/intel_fbdev.c
> @@ -26,6 +26,7 @@
>
> #include <linux/module.h>
> #include <linux/kernel.h>
> +#include <linux/console.h>
> #include <linux/errno.h>
> #include <linux/string.h>
> #include <linux/mm.h>
> @@ -678,6 +679,19 @@ void intel_fbdev_fini(struct drm_device *dev)
> dev_priv->fbdev = NULL;
> }
>
> +struct set_suspend_work {
> + struct work_struct work;
> + struct drm_device *dev;
> + int state;
> +};
> +
> +static void intel_fbdev_set_suspend_worker(struct work_struct *work)
> +{
> + struct set_suspend_work *ss = container_of(work, typeof(*ss), work);
> + intel_fbdev_set_suspend(ss->dev, ss->state);
This still trylocks so ends up busy-looping through launching more work
items. Probably better also do this synchronously.
-Daniel
> + kfree(ss);
> +}
> +
> void intel_fbdev_set_suspend(struct drm_device *dev, int state)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -689,6 +703,24 @@ void intel_fbdev_set_suspend(struct drm_device *dev, int state)
>
> info = ifbdev->helper.fbdev;
>
> + /*
> + * The console lock can be pretty contented on resume due
> + * to all the printk activity. Try to keep it out of the hot
> + * path of resume if possible.
> + */
> + if (!console_trylock()) {
> + struct set_suspend_work *ss;
> +
> + ss = kmalloc(sizeof(*ss), GFP_KERNEL);
> + if (ss) {
> + ss->dev = dev;
> + ss->state = state;
> + INIT_WORK(&ss->work, intel_fbdev_set_suspend_worker);
> + schedule_work(&ss->work);
> + }
> + return;
> + }
> +
> /* On resume from hibernation: If the object is shmemfs backed, it has
> * been restored from swap. If the object is stolen however, it will be
> * full of whatever garbage was left in there.
> @@ -697,6 +729,7 @@ void intel_fbdev_set_suspend(struct drm_device *dev, int state)
> memset_io(info->screen_base, 0, info->screen_size);
>
> fb_set_suspend(info, state);
> + console_unlock();
> }
>
> void intel_fbdev_output_poll_changed(struct drm_device *dev)
> --
> 2.1.0.rc1
>
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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