On Wed, 24 Apr 2013, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> Our rps code relies on the interrupts being off to prevent re-arming
> of the work items at inopportune moments.
>
> Also drop the redundant cancel_work for the main rps work,
> disable_gt_powersave already takes care of that.
>
> Finally add a WARN_ON to ensure we obey that piece of ordering
> constraint. Long term I want to lock down the setup/teardown code in a
> similar way to how we painstakingly check modeset sequence constraints
> already.
>
> v2: Disable polling after hpd handling is shut down - since Egbert's
> hpd irq storm handling the hotplug work can re-arm the polling
> handler. Spotted by Jani Nikula.
Reviewed-by: Jani Nikula <jani.nikula at intel.com>
>
> Cc: Jesse Barnes <jbarnes at virtuousgeek.org>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
> drivers/gpu/drm/i915/intel_display.c | 19 ++++++++++++-------
> drivers/gpu/drm/i915/intel_pm.c | 3 +++
> 2 files changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 74156e2..988e543 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -9530,12 +9530,23 @@ void intel_modeset_cleanup(struct drm_device *dev)
> struct drm_crtc *crtc;
> struct intel_crtc *intel_crtc;
>
> + /*
> + * Interrupts and polling as the first thing to avoid creating havoc.
> + * Too much stuff here (turning of rps, connectors, ...) would
> + * experience fancy races otherwise.
> + */
> + drm_irq_uninstall(dev);
> + cancel_work_sync(&dev_priv->hotplug_work);
> + /*
> + * Due to the hpd irq storm handling the hotplug work can re-arm the
> + * poll handlers. Hence disable polling after hpd handling is shut down.
> + */
> drm_kms_helper_poll_fini(dev);
> +
> mutex_lock(&dev->struct_mutex);
>
> intel_unregister_dsm_handler();
>
> -
> list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
> /* Skip inactive CRTCs */
> if (!crtc->fb)
> @@ -9553,12 +9564,6 @@ void intel_modeset_cleanup(struct drm_device *dev)
>
> mutex_unlock(&dev->struct_mutex);
>
> - /* Disable the irq before mode object teardown, for the irq might
> - * enqueue unpin/hotplug work. */
> - drm_irq_uninstall(dev);
> - cancel_work_sync(&dev_priv->hotplug_work);
> - cancel_work_sync(&dev_priv->rps.work);
> -
> /* flush any delayed tasks or pending work */
> flush_scheduled_work();
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index 8b7f050..bb45122 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3671,6 +3671,9 @@ void intel_disable_gt_powersave(struct drm_device *dev)
> {
> struct drm_i915_private *dev_priv = dev->dev_private;
>
> + /* Interrupts should be disabled already to avoid re-arming. */
> + WARN_ON(dev->irq_enabled);
> +
> if (IS_IRONLAKE_M(dev)) {
> ironlake_disable_drps(dev);
> ironlake_disable_rc6(dev);
> --
> 1.7.10.4
