linux_dsm_epyc7002/drivers/gpu/drm/drm_sysfs.c
Russell King 38d8571dad drm: fix writing to /sys/class/drm/*/status
Writing to a file is supposed to return the number of bytes written.
Returning zero unfortunately causes bash to constantly spin trying
to write to the sysfs file, to such an extent that even ^c and ^z
have no effect.  The only way out of that is to kill the shell and
log back in.  This isn't nice behaviour.

Fix it by returning the number of characters written to sysfs files.

[airlied: used suggestion from Al Viro]
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2015-06-06 08:27:30 +10:00

618 lines
16 KiB
C

/*
* 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.
*
* This file is released under the GPLv2
*
*/
#include <linux/device.h>
#include <linux/kdev_t.h>
#include <linux/gfp.h>
#include <linux/err.h>
#include <linux/export.h>
#include <drm/drm_sysfs.h>
#include <drm/drm_core.h>
#include <drm/drmP.h>
#include "drm_internal.h"
#define to_drm_minor(d) dev_get_drvdata(d)
#define to_drm_connector(d) dev_get_drvdata(d)
static struct device_type drm_sysfs_device_minor = {
.name = "drm_minor"
};
/**
* __drm_class_suspend - internal DRM class suspend routine
* @dev: Linux device to suspend
* @state: power state to enter
*
* Just figures out what the actual struct drm_device associated with
* @dev is and calls its suspend hook, if present.
*/
static int __drm_class_suspend(struct device *dev, pm_message_t state)
{
if (dev->type == &drm_sysfs_device_minor) {
struct drm_minor *drm_minor = to_drm_minor(dev);
struct drm_device *drm_dev = drm_minor->dev;
if (drm_minor->type == DRM_MINOR_LEGACY &&
!drm_core_check_feature(drm_dev, DRIVER_MODESET) &&
drm_dev->driver->suspend)
return drm_dev->driver->suspend(drm_dev, state);
}
return 0;
}
/**
* drm_class_suspend - internal DRM class suspend hook. Simply calls
* __drm_class_suspend() with the correct pm state.
* @dev: Linux device to suspend
*/
static int drm_class_suspend(struct device *dev)
{
return __drm_class_suspend(dev, PMSG_SUSPEND);
}
/**
* drm_class_freeze - internal DRM class freeze hook. Simply calls
* __drm_class_suspend() with the correct pm state.
* @dev: Linux device to freeze
*/
static int drm_class_freeze(struct device *dev)
{
return __drm_class_suspend(dev, PMSG_FREEZE);
}
/**
* drm_class_resume - DRM class resume hook
* @dev: Linux device to resume
*
* Just figures out what the actual struct drm_device associated with
* @dev is and calls its resume hook, if present.
*/
static int drm_class_resume(struct device *dev)
{
if (dev->type == &drm_sysfs_device_minor) {
struct drm_minor *drm_minor = to_drm_minor(dev);
struct drm_device *drm_dev = drm_minor->dev;
if (drm_minor->type == DRM_MINOR_LEGACY &&
!drm_core_check_feature(drm_dev, DRIVER_MODESET) &&
drm_dev->driver->resume)
return drm_dev->driver->resume(drm_dev);
}
return 0;
}
static const struct dev_pm_ops drm_class_dev_pm_ops = {
.suspend = drm_class_suspend,
.resume = drm_class_resume,
.freeze = drm_class_freeze,
};
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,
CORE_NAME " "
__stringify(CORE_MAJOR) "."
__stringify(CORE_MINOR) "."
__stringify(CORE_PATCHLEVEL) " "
CORE_DATE);
/**
* drm_sysfs_create - create a struct drm_sysfs_class structure
* @owner: pointer to the module that is to "own" this struct drm_sysfs_class
* @name: pointer to a string for the name of this class.
*
* This is used to create DRM class pointer that can then be used
* in calls to drm_sysfs_device_add().
*
* Note, the pointer created here is to be destroyed when finished by making a
* call to drm_sysfs_destroy().
*/
struct class *drm_sysfs_create(struct module *owner, char *name)
{
struct class *class;
int err;
class = class_create(owner, name);
if (IS_ERR(class)) {
err = PTR_ERR(class);
goto err_out;
}
class->pm = &drm_class_dev_pm_ops;
err = class_create_file(class, &class_attr_version.attr);
if (err)
goto err_out_class;
class->devnode = drm_devnode;
return class;
err_out_class:
class_destroy(class);
err_out:
return ERR_PTR(err);
}
/**
* drm_sysfs_destroy - destroys DRM class
*
* Destroy the DRM device class.
*/
void drm_sysfs_destroy(void)
{
if ((drm_class == NULL) || (IS_ERR(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_status old_status;
int ret;
ret = mutex_lock_interruptible(&dev->mode_config.mutex);
if (ret)
return ret;
old_status = connector->status;
if (sysfs_streq(buf, "detect")) {
connector->force = 0;
connector->status = connector->funcs->detect(connector, true);
} 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 (ret == 0 && connector->force) {
if (connector->force == DRM_FORCE_ON ||
connector->force == DRM_FORCE_ON_DIGITAL)
connector->status = connector_status_connected;
else
connector->status = connector_status_disconnected;
if (connector->funcs->force)
connector->funcs->force(connector);
}
if (old_status != connector->status) {
DRM_DEBUG_KMS("[CONNECTOR:%d:%s] status updated from %d to %d\n",
connector->base.id,
connector->name,
old_status, connector->status);
dev->mode_config.delayed_event = true;
if (dev->mode_config.poll_enabled)
schedule_delayed_work(&dev->mode_config.output_poll_work,
0);
}
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);
return snprintf(buf, PAGE_SIZE, "%s\n",
drm_get_connector_status_name(connector->status));
}
static ssize_t dpms_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
struct drm_device *dev = connector->dev;
uint64_t dpms_status;
int ret;
ret = drm_object_property_get_value(&connector->base,
dev->mode_config.dpms_property,
&dpms_status);
if (ret)
return 0;
return snprintf(buf, PAGE_SIZE, "%s\n",
drm_get_dpms_name((int)dpms_status));
}
static ssize_t enabled_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
return snprintf(buf, PAGE_SIZE, "%s\n", connector->encoder ? "enabled" :
"disabled");
}
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 = container_of(kobj, struct device, kobj);
struct drm_connector *connector = to_drm_connector(connector_dev);
unsigned char *edid;
size_t size;
if (!connector->edid_blob_ptr)
return 0;
edid = connector->edid_blob_ptr->data;
size = connector->edid_blob_ptr->length;
if (!edid)
return 0;
if (off >= size)
return 0;
if (off + count > size)
count = size - off;
memcpy(buf, edid + off, count);
return count;
}
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;
list_for_each_entry(mode, &connector->modes, head) {
written += snprintf(buf + written, PAGE_SIZE - written, "%s\n",
mode->name);
}
return written;
}
static ssize_t subconnector_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
struct drm_device *dev = connector->dev;
struct drm_property *prop = NULL;
uint64_t subconnector;
int is_tv = 0;
int ret;
switch (connector->connector_type) {
case DRM_MODE_CONNECTOR_DVII:
prop = dev->mode_config.dvi_i_subconnector_property;
break;
case DRM_MODE_CONNECTOR_Composite:
case DRM_MODE_CONNECTOR_SVIDEO:
case DRM_MODE_CONNECTOR_Component:
case DRM_MODE_CONNECTOR_TV:
prop = dev->mode_config.tv_subconnector_property;
is_tv = 1;
break;
default:
DRM_ERROR("Wrong connector type for this property\n");
return 0;
}
if (!prop) {
DRM_ERROR("Unable to find subconnector property\n");
return 0;
}
ret = drm_object_property_get_value(&connector->base, prop, &subconnector);
if (ret)
return 0;
return snprintf(buf, PAGE_SIZE, "%s", is_tv ?
drm_get_tv_subconnector_name((int)subconnector) :
drm_get_dvi_i_subconnector_name((int)subconnector));
}
static ssize_t select_subconnector_show(struct device *device,
struct device_attribute *attr,
char *buf)
{
struct drm_connector *connector = to_drm_connector(device);
struct drm_device *dev = connector->dev;
struct drm_property *prop = NULL;
uint64_t subconnector;
int is_tv = 0;
int ret;
switch (connector->connector_type) {
case DRM_MODE_CONNECTOR_DVII:
prop = dev->mode_config.dvi_i_select_subconnector_property;
break;
case DRM_MODE_CONNECTOR_Composite:
case DRM_MODE_CONNECTOR_SVIDEO:
case DRM_MODE_CONNECTOR_Component:
case DRM_MODE_CONNECTOR_TV:
prop = dev->mode_config.tv_select_subconnector_property;
is_tv = 1;
break;
default:
DRM_ERROR("Wrong connector type for this property\n");
return 0;
}
if (!prop) {
DRM_ERROR("Unable to find select subconnector property\n");
return 0;
}
ret = drm_object_property_get_value(&connector->base, prop, &subconnector);
if (ret)
return 0;
return snprintf(buf, PAGE_SIZE, "%s", is_tv ?
drm_get_tv_select_name((int)subconnector) :
drm_get_dvi_i_select_name((int)subconnector));
}
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
};
/* These attributes are for both DVI-I connectors and all types of tv-out. */
static DEVICE_ATTR_RO(subconnector);
static DEVICE_ATTR_RO(select_subconnector);
static struct attribute *connector_opt_dev_attrs[] = {
&dev_attr_subconnector.attr,
&dev_attr_select_subconnector.attr,
NULL
};
static umode_t connector_opt_dev_is_visible(struct kobject *kobj,
struct attribute *attr, int idx)
{
struct device *dev = kobj_to_dev(kobj);
struct drm_connector *connector = to_drm_connector(dev);
/*
* In the long run it maybe a good idea to make one set of
* optionals per connector type.
*/
switch (connector->connector_type) {
case DRM_MODE_CONNECTOR_DVII:
case DRM_MODE_CONNECTOR_Composite:
case DRM_MODE_CONNECTOR_SVIDEO:
case DRM_MODE_CONNECTOR_Component:
case DRM_MODE_CONNECTOR_TV:
return attr->mode;
}
return 0;
}
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_opt_dev_group = {
.attrs = connector_opt_dev_attrs,
.is_visible = connector_opt_dev_is_visible,
};
static const struct attribute_group *connector_dev_groups[] = {
&connector_dev_group,
&connector_opt_dev_group,
NULL
};
/**
* drm_sysfs_connector_add - add a connector to sysfs
* @connector: connector to add
*
* Create a connector device in sysfs, along with its associated connector
* properties (so far, connection status, dpms, mode list & edid) and
* generate a hotplug event so userspace knows there's a new connector
* available.
*/
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);
}
/* Let userspace know we have a new connector */
drm_sysfs_hotplug_event(dev);
return 0;
}
/**
* drm_sysfs_connector_remove - remove an connector device from sysfs
* @connector: connector to remove
*
* Remove @connector and its associated attributes from sysfs. Note that
* the device model core will take care of sending the "remove" uevent
* at this time, so we don't need to do it.
*
* Note:
* This routine should only be called if the connector was previously
* successfully registered. If @connector hasn't been registered yet,
* you'll likely see a panic somewhere deep in sysfs code when called.
*/
void drm_sysfs_connector_remove(struct drm_connector *connector)
{
if (!connector->kdev)
return;
DRM_DEBUG("removing \"%s\" from sysfs\n",
connector->name);
device_unregister(connector->kdev);
connector->kdev = NULL;
}
/**
* 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.
*/
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);
static void drm_sysfs_release(struct device *dev)
{
kfree(dev);
}
/**
* drm_sysfs_minor_alloc() - Allocate sysfs device for given minor
* @minor: minor to allocate sysfs device for
*
* This allocates a new sysfs device for @minor and returns it. The device is
* not registered nor linked. The caller has to use device_add() and
* device_del() to register and unregister it.
*
* Note that dev_get_drvdata() on the new device will return the minor.
* However, the device does not hold a ref-count to the minor nor to the
* underlying drm_device. This is unproblematic as long as you access the
* private data only in sysfs callbacks. device_del() disables those
* synchronously, so they cannot be called after you cleanup a minor.
*/
struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
{
const char *minor_str;
struct device *kdev;
int r;
if (minor->type == DRM_MINOR_CONTROL)
minor_str = "controlD%d";
else 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 a struct device in the drm class.
*
* @dev: pointer to struct device to register.
*
* @dev should have all relevant members pre-filled with the exception
* of the class member. In particular, the device_type member must
* be set.
*/
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);
void drm_class_device_unregister(struct device *dev)
{
return device_unregister(dev);
}
EXPORT_SYMBOL_GPL(drm_class_device_unregister);