1 files changed, 42 insertions, 10 deletions

diff --git a/drivers/firmware/sysfb.c b/drivers/firmware/sysfb.c
index 880ffcb50088..7c5c03f274b9 100644
--- a/drivers/firmware/sysfb.c
+++ b/drivers/firmware/sysfb.c
@@ -39,6 +39,8 @@ static struct platform_device *pd;
 static DEFINE_MUTEX(disable_lock);
 static bool disabled;
 
+static struct device *sysfb_parent_dev(const struct screen_info *si);
+
 static bool sysfb_unregister(void)
 {
 	if (IS_ERR_OR_NULL(pd))
@@ -52,6 +54,7 @@ static bool sysfb_unregister(void)
 
 /**
  * sysfb_disable() - disable the Generic System Framebuffers support
+ * @dev:	the device to check if non-NULL
  *
  * This disables the registration of system framebuffer devices that match the
  * generic drivers that make use of the system framebuffer set up by firmware.
@@ -61,17 +64,42 @@ static bool sysfb_unregister(void)
  * Context: The function can sleep. A @disable_lock mutex is acquired to serialize
  *          against sysfb_init(), that registers a system framebuffer device.
  */
-void sysfb_disable(void)
+void sysfb_disable(struct device *dev)
 {
+	struct screen_info *si = &screen_info;
+	struct device *parent;
+
 	mutex_lock(&disable_lock);
-	sysfb_unregister();
-	disabled = true;
+	parent = sysfb_parent_dev(si);
+	if (!dev || !parent || dev == parent) {
+		sysfb_unregister();
+		disabled = true;
+	}
 	mutex_unlock(&disable_lock);
 }
 EXPORT_SYMBOL_GPL(sysfb_disable);
 
+/**
+ * sysfb_handles_screen_info() - reports if sysfb handles the global screen_info
+ *
+ * Callers can use sysfb_handles_screen_info() to determine whether the Generic
+ * System Framebuffers (sysfb) can handle the global screen_info data structure
+ * or not. Drivers might need this information to know if they have to setup the
+ * system framebuffer, or if they have to delegate this action to sysfb instead.
+ *
+ * Returns:
+ * True if sysfb handles the global screen_info data structure.
+ */
+bool sysfb_handles_screen_info(void)
+{
+	const struct screen_info *si = &screen_info;
+
+	return !!screen_info_video_type(si);
+}
+EXPORT_SYMBOL_GPL(sysfb_handles_screen_info);
+
 #if defined(CONFIG_PCI)
-static __init bool sysfb_pci_dev_is_enabled(struct pci_dev *pdev)
+static bool sysfb_pci_dev_is_enabled(struct pci_dev *pdev)
 {
 	/*
 	 * TODO: Try to integrate this code into the PCI subsystem
@@ -87,13 +115,13 @@ static __init bool sysfb_pci_dev_is_enabled(struct pci_dev *pdev)
 	return true;
 }
 #else
-static __init bool sysfb_pci_dev_is_enabled(struct pci_dev *pdev)
+static bool sysfb_pci_dev_is_enabled(struct pci_dev *pdev)
 {
 	return false;
 }
 #endif
 
-static __init struct device *sysfb_parent_dev(const struct screen_info *si)
+static struct device *sysfb_parent_dev(const struct screen_info *si)
 {
 	struct pci_dev *pdev;
 
@@ -101,8 +129,10 @@ static __init struct device *sysfb_parent_dev(const struct screen_info *si)
 	if (IS_ERR(pdev)) {
 		return ERR_CAST(pdev);
 	} else if (pdev) {
-		if (!sysfb_pci_dev_is_enabled(pdev))
+		if (!sysfb_pci_dev_is_enabled(pdev)) {
+			pci_dev_put(pdev);
 			return ERR_PTR(-ENODEV);
+		}
 		return &pdev->dev;
 	}
 
@@ -137,7 +167,7 @@ static __init int sysfb_init(void)
 	if (compatible) {
 		pd = sysfb_create_simplefb(si, &mode, parent);
 		if (!IS_ERR(pd))
-			goto unlock_mutex;
+			goto put_device;
 	}
 
 	/* if the FB is incompatible, create a legacy framebuffer device */
@@ -155,7 +185,7 @@ static __init int sysfb_init(void)
 	pd = platform_device_alloc(name, 0);
 	if (!pd) {
 		ret = -ENOMEM;
-		goto unlock_mutex;
+		goto put_device;
 	}
 
 	pd->dev.parent = parent;
@@ -170,9 +200,11 @@ static __init int sysfb_init(void)
 	if (ret)
 		goto err;
 
-	goto unlock_mutex;
+	goto put_device;
 err:
 	platform_device_put(pd);
+put_device:
+	put_device(parent);
 unlock_mutex:
 	mutex_unlock(&disable_lock);
 	return ret;