linux/drivers/gpu/drm/drm_sysfs.c
Jeykumar Sankaran 968d81a64a drm/connector: notify userspace on hotplug after register complete
drm connector notifies userspace on hotplug event prematurely before
late_register and mode_object register completes. This leads to a race
between userspace and kernel on updating the IDR list. So, move the
notification to end of connector register.

Signed-off-by: Jeykumar Sankaran <jsanka@codeaurora.org>
Signed-off-by: Steve Cohen <cohens@codeaurora.org>
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1591155451-10393-1-git-send-email-jsanka@codeaurora.org
2020-06-03 10:24:23 +02:00

448 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* drm_sysfs.c - Modifications to drm_sysfs_class.c to support
* extra sysfs attribute from DRM. Normal drm_sysfs_class
* does not allow adding attributes.
*
* Copyright (c) 2004 Jon Smirl <jonsmirl@gmail.com>
* Copyright (c) 2003-2004 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (c) 2003-2004 IBM Corp.
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/export.h>
#include <linux/gfp.h>
#include <linux/i2c.h>
#include <linux/kdev_t.h>
#include <linux/slab.h>
#include <drm/drm_connector.h>
#include <drm/drm_device.h>
#include <drm/drm_file.h>
#include <drm/drm_modes.h>
#include <drm/drm_print.h>
#include <drm/drm_property.h>
#include <drm/drm_sysfs.h>
#include "drm_internal.h"
#include "drm_crtc_internal.h"
#define to_drm_minor(d) dev_get_drvdata(d)
#define to_drm_connector(d) dev_get_drvdata(d)
/**
* DOC: overview
*
* DRM provides very little additional support to drivers for sysfs
* interactions, beyond just all the standard stuff. Drivers who want to expose
* additional sysfs properties and property groups can attach them at either
* &drm_device.dev or &drm_connector.kdev.
*
* Registration is automatically handled when calling drm_dev_register(), or
* drm_connector_register() in case of hot-plugged connectors. Unregistration is
* also automatically handled by drm_dev_unregister() and
* drm_connector_unregister().
*/
static struct device_type drm_sysfs_device_minor = {
.name = "drm_minor"
};
struct class *drm_class;
static char *drm_devnode(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
}
static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");
/**
* drm_sysfs_init - initialize sysfs helpers
*
* This is used to create the DRM class, which is the implicit parent of any
* other top-level DRM sysfs objects.
*
* You must call drm_sysfs_destroy() to release the allocated resources.
*
* Return: 0 on success, negative error code on failure.
*/
int drm_sysfs_init(void)
{
int err;
drm_class = class_create(THIS_MODULE, "drm");
if (IS_ERR(drm_class))
return PTR_ERR(drm_class);
err = class_create_file(drm_class, &class_attr_version.attr);
if (err) {
class_destroy(drm_class);
drm_class = NULL;
return err;
}
drm_class->devnode = drm_devnode;
return 0;
}
/**
* drm_sysfs_destroy - destroys DRM class
*
* Destroy the DRM device class.
*/
void drm_sysfs_destroy(void)
{
if (IS_ERR_OR_NULL(drm_class))
return;
class_remove_file(drm_class, &class_attr_version.attr);
class_destroy(drm_class);
drm_class = NULL;
}
/*
* Connector properties
*/
static ssize_t status_store(struct device *device,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct drm_connector *connector = to_drm_connector(device);
struct drm_device *dev = connector->dev;
enum drm_connector_force old_force;
int ret;
ret = mutex_lock_interruptible(&dev->mode_config.mutex);
if (ret)
return ret;
old_force = connector->force;
if (sysfs_streq(buf, "detect"))
connector->force = 0;
else if (sysfs_streq(buf, "on"))
connector->force = DRM_FORCE_ON;
else if (sysfs_streq(buf, "on-digital"))
connector->force = DRM_FORCE_ON_DIGITAL;
else if (sysfs_streq(buf, "off"))
connector->force = DRM_FORCE_OFF;
else
ret = -EINVAL;
if (old_force != connector->force || !connector->force) {
DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force updated from %d to %d or reprobing\n",
connector->base.id,
connector->name,
old_force, connector->force);
connector->funcs->fill_modes(connector,
dev->mode_config.max_width,
dev->mode_config.max_height);
}
mutex_unlock(&dev->mode_config.mutex);
return ret ? ret : count;
}
static ssize_t status_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
enum drm_connector_status status;
status = READ_ONCE(connector->status);
return snprintf(buf, PAGE_SIZE, "%s\n",
drm_get_connector_status_name(status));
}
static ssize_t dpms_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
int dpms;
dpms = READ_ONCE(connector->dpms);
return snprintf(buf, PAGE_SIZE, "%s\n",
drm_get_dpms_name(dpms));
}
static ssize_t enabled_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
bool enabled;
enabled = READ_ONCE(connector->encoder);
return snprintf(buf, PAGE_SIZE, enabled ? "enabled\n" : "disabled\n");
}
static ssize_t edid_show(struct file *filp, struct kobject *kobj,
struct bin_attribute *attr, char *buf, loff_t off,
size_t count)
{
struct device *connector_dev = kobj_to_dev(kobj);
struct drm_connector *connector = to_drm_connector(connector_dev);
unsigned char *edid;
size_t size;
ssize_t ret = 0;
mutex_lock(&connector->dev->mode_config.mutex);
if (!connector->edid_blob_ptr)
goto unlock;
edid = connector->edid_blob_ptr->data;
size = connector->edid_blob_ptr->length;
if (!edid)
goto unlock;
if (off >= size)
goto unlock;
if (off + count > size)
count = size - off;
memcpy(buf, edid + off, count);
ret = count;
unlock:
mutex_unlock(&connector->dev->mode_config.mutex);
return ret;
}
static ssize_t modes_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
struct drm_display_mode *mode;
int written = 0;
mutex_lock(&connector->dev->mode_config.mutex);
list_for_each_entry(mode, &connector->modes, head) {
written += scnprintf(buf + written, PAGE_SIZE - written, "%s\n",
mode->name);
}
mutex_unlock(&connector->dev->mode_config.mutex);
return written;
}
static DEVICE_ATTR_RW(status);
static DEVICE_ATTR_RO(enabled);
static DEVICE_ATTR_RO(dpms);
static DEVICE_ATTR_RO(modes);
static struct attribute *connector_dev_attrs[] = {
&dev_attr_status.attr,
&dev_attr_enabled.attr,
&dev_attr_dpms.attr,
&dev_attr_modes.attr,
NULL
};
static struct bin_attribute edid_attr = {
.attr.name = "edid",
.attr.mode = 0444,
.size = 0,
.read = edid_show,
};
static struct bin_attribute *connector_bin_attrs[] = {
&edid_attr,
NULL
};
static const struct attribute_group connector_dev_group = {
.attrs = connector_dev_attrs,
.bin_attrs = connector_bin_attrs,
};
static const struct attribute_group *connector_dev_groups[] = {
&connector_dev_group,
NULL
};
int drm_sysfs_connector_add(struct drm_connector *connector)
{
struct drm_device *dev = connector->dev;
if (connector->kdev)
return 0;
connector->kdev =
device_create_with_groups(drm_class, dev->primary->kdev, 0,
connector, connector_dev_groups,
"card%d-%s", dev->primary->index,
connector->name);
DRM_DEBUG("adding \"%s\" to sysfs\n",
connector->name);
if (IS_ERR(connector->kdev)) {
DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev));
return PTR_ERR(connector->kdev);
}
if (connector->ddc)
return sysfs_create_link(&connector->kdev->kobj,
&connector->ddc->dev.kobj, "ddc");
return 0;
}
void drm_sysfs_connector_remove(struct drm_connector *connector)
{
if (!connector->kdev)
return;
if (connector->ddc)
sysfs_remove_link(&connector->kdev->kobj, "ddc");
DRM_DEBUG("removing \"%s\" from sysfs\n",
connector->name);
device_unregister(connector->kdev);
connector->kdev = NULL;
}
void drm_sysfs_lease_event(struct drm_device *dev)
{
char *event_string = "LEASE=1";
char *envp[] = { event_string, NULL };
DRM_DEBUG("generating lease event\n");
kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
}
/**
* drm_sysfs_hotplug_event - generate a DRM uevent
* @dev: DRM device
*
* Send a uevent for the DRM device specified by @dev. Currently we only
* set HOTPLUG=1 in the uevent environment, but this could be expanded to
* deal with other types of events.
*
* Any new uapi should be using the drm_sysfs_connector_status_event()
* for uevents on connector status change.
*/
void drm_sysfs_hotplug_event(struct drm_device *dev)
{
char *event_string = "HOTPLUG=1";
char *envp[] = { event_string, NULL };
DRM_DEBUG("generating hotplug event\n");
kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
}
EXPORT_SYMBOL(drm_sysfs_hotplug_event);
/**
* drm_sysfs_connector_status_event - generate a DRM uevent for connector
* property status change
* @connector: connector on which property status changed
* @property: connector property whose status changed.
*
* Send a uevent for the DRM device specified by @dev. Currently we
* set HOTPLUG=1 and connector id along with the attached property id
* related to the status change.
*/
void drm_sysfs_connector_status_event(struct drm_connector *connector,
struct drm_property *property)
{
struct drm_device *dev = connector->dev;
char hotplug_str[] = "HOTPLUG=1", conn_id[21], prop_id[21];
char *envp[4] = { hotplug_str, conn_id, prop_id, NULL };
WARN_ON(!drm_mode_obj_find_prop_id(&connector->base,
property->base.id));
snprintf(conn_id, ARRAY_SIZE(conn_id),
"CONNECTOR=%u", connector->base.id);
snprintf(prop_id, ARRAY_SIZE(prop_id),
"PROPERTY=%u", property->base.id);
DRM_DEBUG("generating connector status event\n");
kobject_uevent_env(&dev->primary->kdev->kobj, KOBJ_CHANGE, envp);
}
EXPORT_SYMBOL(drm_sysfs_connector_status_event);
static void drm_sysfs_release(struct device *dev)
{
kfree(dev);
}
struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
{
const char *minor_str;
struct device *kdev;
int r;
if (minor->type == DRM_MINOR_RENDER)
minor_str = "renderD%d";
else
minor_str = "card%d";
kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
if (!kdev)
return ERR_PTR(-ENOMEM);
device_initialize(kdev);
kdev->devt = MKDEV(DRM_MAJOR, minor->index);
kdev->class = drm_class;
kdev->type = &drm_sysfs_device_minor;
kdev->parent = minor->dev->dev;
kdev->release = drm_sysfs_release;
dev_set_drvdata(kdev, minor);
r = dev_set_name(kdev, minor_str, minor->index);
if (r < 0)
goto err_free;
return kdev;
err_free:
put_device(kdev);
return ERR_PTR(r);
}
/**
* drm_class_device_register - register new device with the DRM sysfs class
* @dev: device to register
*
* Registers a new &struct device within the DRM sysfs class. Essentially only
* used by ttm to have a place for its global settings. Drivers should never use
* this.
*/
int drm_class_device_register(struct device *dev)
{
if (!drm_class || IS_ERR(drm_class))
return -ENOENT;
dev->class = drm_class;
return device_register(dev);
}
EXPORT_SYMBOL_GPL(drm_class_device_register);
/**
* drm_class_device_unregister - unregister device with the DRM sysfs class
* @dev: device to unregister
*
* Unregisters a &struct device from the DRM sysfs class. Essentially only used
* by ttm to have a place for its global settings. Drivers should never use
* this.
*/
void drm_class_device_unregister(struct device *dev)
{
return device_unregister(dev);
}
EXPORT_SYMBOL_GPL(drm_class_device_unregister);