drm/i915: split intel_modeset_driver_remove() to pre/post irq uninstall

Split intel_modeset_driver_remove() to two, the part with working irqs
before irq uninstall, and the part after irq uninstall. Move
irq_unintall() closer to the layer it belongs.

The error path in i915_driver_modeset_probe() looks obviously weird
after this, but remains as good or broken as it ever was. No functional
changes.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200214135058.7580-1-jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_display.c

@@ -18923,6 +18923,7 @@ static void intel_hpd_poll_fini(struct drm_i915_private *i915)
 	drm_connector_list_iter_end(&conn_iter);
 }
 
+/* part #1: call before irq uninstall */
 void intel_modeset_driver_remove(struct drm_i915_private *i915)
 {
 	flush_workqueue(i915->flip_wq);
@@ -18930,14 +18931,11 @@ void intel_modeset_driver_remove(struct drm_i915_private *i915)
 
 	flush_work(&i915->atomic_helper.free_work);
 	WARN_ON(!llist_empty(&i915->atomic_helper.free_list));
+}
 
-	/*
-	 * Interrupts and polling as the first thing to avoid creating havoc.
-	 * Too much stuff here (turning of connectors, ...) would
-	 * experience fancy races otherwise.
-	 */
-	intel_irq_uninstall(i915);
-
+/* part #2: call after irq uninstall */
+void intel_modeset_driver_remove_noirq(struct drm_i915_private *i915)
+{
 	/*
 	 * 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.

drivers/gpu/drm/i915/display/intel_display.h

@@ -616,6 +616,7 @@ intel_format_info_is_yuv_semiplanar(const struct drm_format_info *info,
 void intel_modeset_init_hw(struct drm_i915_private *i915);
 int intel_modeset_init(struct drm_i915_private *i915);
 void intel_modeset_driver_remove(struct drm_i915_private *i915);
+void intel_modeset_driver_remove_noirq(struct drm_i915_private *i915);
 void intel_display_resume(struct drm_device *dev);
 void intel_init_pch_refclk(struct drm_i915_private *dev_priv);
 

drivers/gpu/drm/i915/i915_drv.c

@@ -272,6 +272,9 @@ static int i915_driver_modeset_probe(struct drm_i915_private *i915)
 	i915_gem_driver_release(i915);
 cleanup_modeset:
 	intel_modeset_driver_remove(i915);
+	intel_irq_uninstall(i915);
+	intel_modeset_driver_remove_noirq(i915);
+	goto cleanup_csr;
 cleanup_irq:
 	intel_irq_uninstall(i915);
 cleanup_csr:
@@ -288,6 +291,8 @@ static void i915_driver_modeset_remove(struct drm_i915_private *i915)
 
 	intel_irq_uninstall(i915);
 
+	intel_modeset_driver_remove_noirq(i915);
+
 	intel_bios_driver_remove(i915);
 
 	intel_vga_unregister(i915);