drm/i915: restore only the mode of this driver on lastclose (v2)

BugLink: https://bugs.launchpad.net/bugs/848687

i915 calls the panic handler function on last close to reset the modes,
however this is a really bad idea for multi-gpu machines, esp shareable
gpus machines. So add a new entry point for the driver to just restore
its own fbcon mode.

v2: move code into fb helper, fix panic code to block mode change on
powered off GPUs.

[airlied: this hits drm core and I wrote it and it was reviewed on intel-gfx
 so really I signed it off twice ;-).]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit e8e7a2b8ccfdae0d4cb6bd25824bbedcd42da316)

Signed-off-by: Evan Broder <ebroder@mokafive.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index f73ef43..efe756e 100644 (file)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -342,9 +342,22 @@ int drm_fb_helper_debug_leave(struct fb_info *info)
 }
 EXPORT_SYMBOL(drm_fb_helper_debug_leave);
 
+bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper)
+{
+       bool error = false;
+       int i, ret;
+       for (i = 0; i < fb_helper->crtc_count; i++) {
+               struct drm_mode_set *mode_set = &fb_helper->crtc_info[i].mode_set;
+               ret = drm_crtc_helper_set_config(mode_set);
+               if (ret)
+                       error = true;
+       }
+       return error;
+}
+EXPORT_SYMBOL(drm_fb_helper_restore_fbdev_mode);
+
 bool drm_fb_helper_force_kernel_mode(void)
 {
-       int i = 0;
        bool ret, error = false;
        struct drm_fb_helper *helper;
 
@@ -352,12 +365,12 @@ bool drm_fb_helper_force_kernel_mode(void)
                return false;
 
        list_for_each_entry(helper, &kernel_fb_helper_list, kernel_fb_list) {
-               for (i = 0; i < helper->crtc_count; i++) {
-                       struct drm_mode_set *mode_set = &helper->crtc_info[i].mode_set;
-                       ret = drm_crtc_helper_set_config(mode_set);
-                       if (ret)
-                               error = true;
-               }
+               if (helper->dev->switch_power_state == DRM_SWITCH_POWER_OFF)
+                       continue;
+
+               ret = drm_fb_helper_restore_fbdev_mode(helper);
+               if (ret)
+                       error = true;
        }
        return error;
 }

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index e33d9be..8159020 100644 (file)
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -2191,7 +2191,7 @@ void i915_driver_lastclose(struct drm_device * dev)
        drm_i915_private_t *dev_priv = dev->dev_private;
 
        if (!dev_priv || drm_core_check_feature(dev, DRIVER_MODESET)) {
-               drm_fb_helper_restore();
+               intel_fb_restore_mode(dev);
                vga_switcheroo_process_delayed_switch();
                return;
        }

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 2c43104..0d6cf14 100644 (file)
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -329,4 +329,5 @@ extern int intel_overlay_attrs(struct drm_device *dev, void *data,
                               struct drm_file *file_priv);
 
 extern void intel_fb_output_poll_changed(struct drm_device *dev);
+extern void intel_fb_restore_mode(struct drm_device *dev);
 #endif /* __INTEL_DRV_H__ */

diff --git a/drivers/gpu/drm/i915/intel_fb.c b/drivers/gpu/drm/i915/intel_fb.c
index 5127827..ec49bae 100644 (file)
--- a/drivers/gpu/drm/i915/intel_fb.c
+++ b/drivers/gpu/drm/i915/intel_fb.c
@@ -264,3 +264,13 @@ void intel_fb_output_poll_changed(struct drm_device *dev)
        drm_i915_private_t *dev_priv = dev->dev_private;
        drm_fb_helper_hotplug_event(&dev_priv->fbdev->helper);
 }
+
+void intel_fb_restore_mode(struct drm_device *dev)
+{
+       int ret;
+       drm_i915_private_t *dev_priv = dev->dev_private;
+
+       ret = drm_fb_helper_restore_fbdev_mode(&dev_priv->fbdev->helper);
+       if (ret)
+               DRM_DEBUG("failed to restore crtc mode\n");
+}

diff --git a/include/drm/drm_fb_helper.h b/include/drm/drm_fb_helper.h
index f22e7fe..ade09d7 100644 (file)
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@@ -118,6 +118,7 @@ int drm_fb_helper_setcolreg(unsigned regno,
                            unsigned transp,
                            struct fb_info *info);
 
+bool drm_fb_helper_restore_fbdev_mode(struct drm_fb_helper *fb_helper);
 void drm_fb_helper_restore(void);
 void drm_fb_helper_fill_var(struct fb_info *info, struct drm_fb_helper *fb_helper,
                            uint32_t fb_width, uint32_t fb_height);