[BACKPORT 4.19.y 3/3] drm/tilcdc: Register cpufreq notifier after we have initialized crtc

From: Mathieu Poirier
Date: Thu Aug 29 2019 - 16:00:13 EST


From: Jyri Sarha <jsarha@xxxxxx>

commit 432973fd3a20102840d5f7e61af9f1a03c217a4c upstream

Register cpufreq notifier after we have initialized the crtc and
unregister it before we remove the ctrc. Receiving a cpufreq notify
without crtc causes a crash.

Reported-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
Signed-off-by: Jyri Sarha <jsarha@xxxxxx>
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
drivers/gpu/drm/tilcdc/tilcdc_drv.c | 34 ++++++++++++++---------------
1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index 0fb300d41a09..e1868776da25 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -184,6 +184,12 @@ static void tilcdc_fini(struct drm_device *dev)
{
struct tilcdc_drm_private *priv = dev->dev_private;

+#ifdef CONFIG_CPU_FREQ
+ if (priv->freq_transition.notifier_call)
+ cpufreq_unregister_notifier(&priv->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+#endif
+
if (priv->crtc)
tilcdc_crtc_shutdown(priv->crtc);

@@ -198,12 +204,6 @@ static void tilcdc_fini(struct drm_device *dev)
drm_mode_config_cleanup(dev);
tilcdc_remove_external_device(dev);

-#ifdef CONFIG_CPU_FREQ
- if (priv->freq_transition.notifier_call)
- cpufreq_unregister_notifier(&priv->freq_transition,
- CPUFREQ_TRANSITION_NOTIFIER);
-#endif
-
if (priv->clk)
clk_put(priv->clk);

@@ -274,17 +274,6 @@ static int tilcdc_init(struct drm_driver *ddrv, struct device *dev)
goto init_failed;
}

-#ifdef CONFIG_CPU_FREQ
- priv->freq_transition.notifier_call = cpufreq_transition;
- ret = cpufreq_register_notifier(&priv->freq_transition,
- CPUFREQ_TRANSITION_NOTIFIER);
- if (ret) {
- dev_err(dev, "failed to register cpufreq notifier\n");
- priv->freq_transition.notifier_call = NULL;
- goto init_failed;
- }
-#endif
-
if (of_property_read_u32(node, "max-bandwidth", &priv->max_bandwidth))
priv->max_bandwidth = TILCDC_DEFAULT_MAX_BANDWIDTH;

@@ -361,6 +350,17 @@ static int tilcdc_init(struct drm_driver *ddrv, struct device *dev)
}
modeset_init(ddev);

+#ifdef CONFIG_CPU_FREQ
+ priv->freq_transition.notifier_call = cpufreq_transition;
+ ret = cpufreq_register_notifier(&priv->freq_transition,
+ CPUFREQ_TRANSITION_NOTIFIER);
+ if (ret) {
+ dev_err(dev, "failed to register cpufreq notifier\n");
+ priv->freq_transition.notifier_call = NULL;
+ goto init_failed;
+ }
+#endif
+
if (priv->is_componentized) {
ret = component_bind_all(dev, ddev);
if (ret < 0)
--
2.17.1