summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--Documentation/driver-api/firmware/other_interfaces.rst6
-rw-r--r--drivers/firmware/sysfb.c58
-rw-r--r--drivers/firmware/sysfb_simplefb.c16
-rw-r--r--drivers/gpu/drm/vc4/vc4_perfmon.c9
-rw-r--r--drivers/video/fbdev/core/fbmem.c12
-rw-r--r--include/linux/sysfb.h22
6 files changed, 99 insertions, 24 deletions
diff --git a/Documentation/driver-api/firmware/other_interfaces.rst b/Documentation/driver-api/firmware/other_interfaces.rst
index b81794e0cfbb..06ac89adaafb 100644
--- a/Documentation/driver-api/firmware/other_interfaces.rst
+++ b/Documentation/driver-api/firmware/other_interfaces.rst
@@ -13,6 +13,12 @@ EDD Interfaces
.. kernel-doc:: drivers/firmware/edd.c
:internal:
+Generic System Framebuffers Interface
+-------------------------------------
+
+.. kernel-doc:: drivers/firmware/sysfb.c
+ :export:
+
Intel Stratix10 SoC Service Layer
---------------------------------
Some features of the Intel Stratix10 SoC require a level of privilege
diff --git a/drivers/firmware/sysfb.c b/drivers/firmware/sysfb.c
index 2bfbb05f7d89..1f276f108cc9 100644
--- a/drivers/firmware/sysfb.c
+++ b/drivers/firmware/sysfb.c
@@ -34,21 +34,59 @@
#include <linux/screen_info.h>
#include <linux/sysfb.h>
+static struct platform_device *pd;
+static DEFINE_MUTEX(disable_lock);
+static bool disabled;
+
+static bool sysfb_unregister(void)
+{
+ if (IS_ERR_OR_NULL(pd))
+ return false;
+
+ platform_device_unregister(pd);
+ pd = NULL;
+
+ return true;
+}
+
+/**
+ * sysfb_disable() - disable the Generic System Framebuffers support
+ *
+ * This disables the registration of system framebuffer devices that match the
+ * generic drivers that make use of the system framebuffer set up by firmware.
+ *
+ * It also unregisters a device if this was already registered by sysfb_init().
+ *
+ * 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)
+{
+ mutex_lock(&disable_lock);
+ sysfb_unregister();
+ disabled = true;
+ mutex_unlock(&disable_lock);
+}
+EXPORT_SYMBOL_GPL(sysfb_disable);
+
static __init int sysfb_init(void)
{
struct screen_info *si = &screen_info;
struct simplefb_platform_data mode;
- struct platform_device *pd;
const char *name;
bool compatible;
- int ret;
+ int ret = 0;
+
+ mutex_lock(&disable_lock);
+ if (disabled)
+ goto unlock_mutex;
/* try to create a simple-framebuffer device */
compatible = sysfb_parse_mode(si, &mode);
if (compatible) {
- ret = sysfb_create_simplefb(si, &mode);
- if (!ret)
- return 0;
+ pd = sysfb_create_simplefb(si, &mode);
+ if (!IS_ERR(pd))
+ goto unlock_mutex;
}
/* if the FB is incompatible, create a legacy framebuffer device */
@@ -60,8 +98,10 @@ static __init int sysfb_init(void)
name = "platform-framebuffer";
pd = platform_device_alloc(name, 0);
- if (!pd)
- return -ENOMEM;
+ if (!pd) {
+ ret = -ENOMEM;
+ goto unlock_mutex;
+ }
sysfb_apply_efi_quirks(pd);
@@ -73,9 +113,11 @@ static __init int sysfb_init(void)
if (ret)
goto err;
- return 0;
+ goto unlock_mutex;
err:
platform_device_put(pd);
+unlock_mutex:
+ mutex_unlock(&disable_lock);
return ret;
}
diff --git a/drivers/firmware/sysfb_simplefb.c b/drivers/firmware/sysfb_simplefb.c
index bda8712bfd8c..a353e27f83f5 100644
--- a/drivers/firmware/sysfb_simplefb.c
+++ b/drivers/firmware/sysfb_simplefb.c
@@ -57,8 +57,8 @@ __init bool sysfb_parse_mode(const struct screen_info *si,
return false;
}
-__init int sysfb_create_simplefb(const struct screen_info *si,
- const struct simplefb_platform_data *mode)
+__init struct platform_device *sysfb_create_simplefb(const struct screen_info *si,
+ const struct simplefb_platform_data *mode)
{
struct platform_device *pd;
struct resource res;
@@ -76,7 +76,7 @@ __init int sysfb_create_simplefb(const struct screen_info *si,
base |= (u64)si->ext_lfb_base << 32;
if (!base || (u64)(resource_size_t)base != base) {
printk(KERN_DEBUG "sysfb: inaccessible VRAM base\n");
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
}
/*
@@ -93,7 +93,7 @@ __init int sysfb_create_simplefb(const struct screen_info *si,
length = mode->height * mode->stride;
if (length > size) {
printk(KERN_WARNING "sysfb: VRAM smaller than advertised\n");
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
}
length = PAGE_ALIGN(length);
@@ -104,11 +104,11 @@ __init int sysfb_create_simplefb(const struct screen_info *si,
res.start = base;
res.end = res.start + length - 1;
if (res.end <= res.start)
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
pd = platform_device_alloc("simple-framebuffer", 0);
if (!pd)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
sysfb_apply_efi_quirks(pd);
@@ -124,10 +124,10 @@ __init int sysfb_create_simplefb(const struct screen_info *si,
if (ret)
goto err_put_device;
- return 0;
+ return pd;
err_put_device:
platform_device_put(pd);
- return ret;
+ return ERR_PTR(ret);
}
diff --git a/drivers/gpu/drm/vc4/vc4_perfmon.c b/drivers/gpu/drm/vc4/vc4_perfmon.c
index c7f5adb6bcf8..79a74184d732 100644
--- a/drivers/gpu/drm/vc4/vc4_perfmon.c
+++ b/drivers/gpu/drm/vc4/vc4_perfmon.c
@@ -17,13 +17,16 @@
void vc4_perfmon_get(struct vc4_perfmon *perfmon)
{
- struct vc4_dev *vc4 = perfmon->dev;
+ struct vc4_dev *vc4;
+ if (!perfmon)
+ return;
+
+ vc4 = perfmon->dev;
if (WARN_ON_ONCE(vc4->is_vc5))
return;
- if (perfmon)
- refcount_inc(&perfmon->refcnt);
+ refcount_inc(&perfmon->refcnt);
}
void vc4_perfmon_put(struct vc4_perfmon *perfmon)
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index afa2863670f3..8afc4538558c 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -19,6 +19,7 @@
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/slab.h>
+#include <linux/sysfb.h>
#include <linux/mm.h>
#include <linux/mman.h>
#include <linux/vt.h>
@@ -1752,6 +1753,17 @@ int remove_conflicting_framebuffers(struct apertures_struct *a,
do_free = true;
}
+ /*
+ * If a driver asked to unregister a platform device registered by
+ * sysfb, then can be assumed that this is a driver for a display
+ * that is set up by the system firmware and has a generic driver.
+ *
+ * Drivers for devices that don't have a generic driver will never
+ * ask for this, so let's assume that a real driver for the display
+ * was already probed and prevent sysfb to register devices later.
+ */
+ sysfb_disable();
+
mutex_lock(&registration_lock);
do_remove_conflicting_framebuffers(a, name, primary);
mutex_unlock(&registration_lock);
diff --git a/include/linux/sysfb.h b/include/linux/sysfb.h
index b0dcfa26d07b..8ba8b5be5567 100644
--- a/include/linux/sysfb.h
+++ b/include/linux/sysfb.h
@@ -55,6 +55,18 @@ struct efifb_dmi_info {
int flags;
};
+#ifdef CONFIG_SYSFB
+
+void sysfb_disable(void);
+
+#else /* CONFIG_SYSFB */
+
+static inline void sysfb_disable(void)
+{
+}
+
+#endif /* CONFIG_SYSFB */
+
#ifdef CONFIG_EFI
extern struct efifb_dmi_info efifb_dmi_list[];
@@ -72,8 +84,8 @@ static inline void sysfb_apply_efi_quirks(struct platform_device *pd)
bool sysfb_parse_mode(const struct screen_info *si,
struct simplefb_platform_data *mode);
-int sysfb_create_simplefb(const struct screen_info *si,
- const struct simplefb_platform_data *mode);
+struct platform_device *sysfb_create_simplefb(const struct screen_info *si,
+ const struct simplefb_platform_data *mode);
#else /* CONFIG_SYSFB_SIMPLE */
@@ -83,10 +95,10 @@ static inline bool sysfb_parse_mode(const struct screen_info *si,
return false;
}
-static inline int sysfb_create_simplefb(const struct screen_info *si,
- const struct simplefb_platform_data *mode)
+static inline struct platform_device *sysfb_create_simplefb(const struct screen_info *si,
+ const struct simplefb_platform_data *mode)
{
- return -EINVAL;
+ return ERR_PTR(-EINVAL);
}
#endif /* CONFIG_SYSFB_SIMPLE */