[PATCH v6 7/7] drm/vkms Add hotplug support via configfs to VKMS.
Brandon Ross Pollack
brpol at chromium.org
Thu Sep 21 03:44:10 UTC 2023
Sorry, these tests are actually running in the chromeOS infrastructure
environment! A similar test can be written in IGT (and I think is in
the other chain that Marius published)
On Thu, Sep 21, 2023 at 3:03 AM Helen Koike <helen.koike at collabora.com> wrote:
>
> Hello!
>
> Thanks for the patch.
>
> On 29/08/2023 02:30, Brandon Pollack wrote:
> > This change adds the ability to read or write a "1" or a "0" to the
> > newly added "connected" attribute of a connector in the vkms entry in
> > configfs.
> >
> > A write will trigger a call to drm_kms_helper_hotplug_event, causing a
> > hotplug uevent.
> >
> > With this we can write virtualized multidisplay tests that involve
> > hotplugging displays (eg recompositing windows when a monitor is turned
> > off).
>
> Are these tests going to be added in igt?
>
> I was just wondering if it requires any special thing for drm ci:
>
> https://lists.freedesktop.org/archives/dri-devel/2023-September/423719.html
>
> (btw, it would be awesome of you could test your changes with drm ci :)
>
> Regards,
> Helen
>
> >
> > Signed-off-by: Brandon Pollack <brpol at chromium.org>
> > ---
> > Documentation/gpu/vkms.rst | 2 +-
> > drivers/gpu/drm/vkms/vkms_configfs.c | 68 ++++++++++++++++++++++++++--
> > drivers/gpu/drm/vkms/vkms_drv.h | 11 +++++
> > drivers/gpu/drm/vkms/vkms_output.c | 47 ++++++++++++++++++-
> > 4 files changed, 123 insertions(+), 5 deletions(-)
> >
> > diff --git a/Documentation/gpu/vkms.rst b/Documentation/gpu/vkms.rst
> > index c3875bf66dba..7f715097539c 100644
> > --- a/Documentation/gpu/vkms.rst
> > +++ b/Documentation/gpu/vkms.rst
> > @@ -145,7 +145,7 @@ We want to be able to manipulate vkms instances without having to reload the
> > module. Such configuration can be added as extensions to vkms's ConfigFS
> > support. Use-cases:
> >
> > -- Hotplug/hotremove connectors on the fly (to be able to test DP MST handling
> > +- Hotremove connectors on the fly (to be able to test DP MST handling
> > of compositors).
> >
> > - Change output configuration: Plug/unplug screens, change EDID, allow changing
> > diff --git a/drivers/gpu/drm/vkms/vkms_configfs.c b/drivers/gpu/drm/vkms/vkms_configfs.c
> > index bc35dcc47585..d231e28101ae 100644
> > --- a/drivers/gpu/drm/vkms/vkms_configfs.c
> > +++ b/drivers/gpu/drm/vkms/vkms_configfs.c
> > @@ -1,5 +1,6 @@
> > // SPDX-License-Identifier: GPL-2.0+
> >
> > +#include "drm/drm_probe_helper.h"
> > #include <linux/configfs.h>
> > #include <linux/mutex.h>
> > #include <linux/platform_device.h>
> > @@ -40,6 +41,7 @@
> > * `-- vkms
> > * `-- test
> > * |-- connectors
> > + * `-- connected
> > * |-- crtcs
> > * |-- encoders
> > * |-- planes
> > @@ -89,6 +91,14 @@
> > *
> > * echo 1 > /config/vkms/test/enabled
> > *
> > + * By default no display is "connected" so to connect a connector you'll also
> > + * have to write 1 to a connectors "connected" attribute::
> > + *
> > + * echo 1 > /config/vkms/test/connectors/connector/connected
> > + *
> > + * One can verify that this is worked using the `modetest` utility or the
> > + * equivalent for your platform.
> > + *
> > * When you're done with the virtual device, you can clean up the device like
> > * so::
> > *
> > @@ -236,7 +246,58 @@ static void add_possible_encoders(struct config_group *parent,
> >
> > /* Connector item, e.g. /config/vkms/device/connectors/ID */
> >
> > +static ssize_t connector_connected_show(struct config_item *item, char *buf)
> > +{
> > + struct vkms_config_connector *connector =
> > + item_to_config_connector(item);
> > + struct vkms_configfs *configfs = connector_item_to_configfs(item);
> > + bool connected = false;
> > +
> > + mutex_lock(&configfs->lock);
> > + connected = connector->connected;
> > + mutex_unlock(&configfs->lock);
> > +
> > + return sprintf(buf, "%d\n", connected);
> > +}
> > +
> > +static ssize_t connector_connected_store(struct config_item *item,
> > + const char *buf, size_t len)
> > +{
> > + struct vkms_config_connector *connector =
> > + item_to_config_connector(item);
> > + struct vkms_configfs *configfs = connector_item_to_configfs(item);
> > + int val, ret;
> > +
> > + ret = kstrtouint(buf, 10, &val);
> > + if (ret)
> > + return ret;
> > +
> > + if (val != 1 && val != 0)
> > + return -EINVAL;
> > +
> > + mutex_lock(&configfs->lock);
> > + connector->connected = val;
> > + if (!connector->connector) {
> > + pr_info("VKMS Device %s is not yet enabled, connector will be enabled on start",
> > + configfs->device_group.cg_item.ci_name);
> > + }
> > + mutex_unlock(&configfs->lock);
> > +
> > + if (connector->connector)
> > + drm_kms_helper_hotplug_event(connector->connector->dev);
> > +
> > + return len;
> > +}
> > +
> > +CONFIGFS_ATTR(connector_, connected);
> > +
> > +static struct configfs_attribute *connector_attrs[] = {
> > + &connector_attr_connected,
> > + NULL,
> > +};
> > +
> > static struct config_item_type connector_type = {
> > + .ct_attrs = connector_attrs,
> > .ct_owner = THIS_MODULE,
> > };
> >
> > @@ -264,7 +325,7 @@ static ssize_t plane_type_show(struct config_item *item, char *buf)
> > plane_type = plane->type;
> > mutex_unlock(&configfs->lock);
> >
> > - return sprintf(buf, "%u", plane_type);
> > + return sprintf(buf, "%u\n", plane_type);
> > }
> >
> > static ssize_t plane_type_store(struct config_item *item, const char *buf,
> > @@ -319,6 +380,7 @@ static struct config_group *connectors_group_make(struct config_group *group,
> > &connector_type);
> > add_possible_encoders(&connector->config_group,
> > &connector->possible_encoders.group);
> > + connector->connected = false;
> >
> > return &connector->config_group;
> > }
> > @@ -500,7 +562,7 @@ static ssize_t device_enabled_show(struct config_item *item, char *buf)
> > is_enabled = configfs->vkms_device != NULL;
> > mutex_unlock(&configfs->lock);
> >
> > - return sprintf(buf, "%d", is_enabled);
> > + return sprintf(buf, "%d\n", is_enabled);
> > }
> >
> > static ssize_t device_enabled_store(struct config_item *item, const char *buf,
> > @@ -557,7 +619,7 @@ static ssize_t device_id_show(struct config_item *item, char *buf)
> >
> > mutex_unlock(&configfs->lock);
> >
> > - return sprintf(buf, "%d", id);
> > + return sprintf(buf, "%d\n", id);
> > }
> >
> > CONFIGFS_ATTR_RO(device_, id);
> > diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
> > index 2b9545ada9c2..5336281f397e 100644
> > --- a/drivers/gpu/drm/vkms/vkms_drv.h
> > +++ b/drivers/gpu/drm/vkms/vkms_drv.h
> > @@ -3,6 +3,7 @@
> > #ifndef _VKMS_DRV_H_
> > #define _VKMS_DRV_H_
> >
> > +#include "drm/drm_connector.h"
> > #include <linux/configfs.h>
> > #include <linux/hrtimer.h>
> >
> > @@ -147,7 +148,9 @@ struct vkms_config_links {
> >
> > struct vkms_config_connector {
> > struct config_group config_group;
> > + struct drm_connector *connector;
> > struct vkms_config_links possible_encoders;
> > + bool connected;
> > };
> >
> > struct vkms_config_crtc {
> > @@ -220,6 +223,10 @@ struct vkms_device {
> > #define item_to_configfs(item) \
> > container_of(to_config_group(item), struct vkms_configfs, device_group)
> >
> > +#define connector_item_to_configfs(item) \
> > + container_of(to_config_group(item->ci_parent), struct vkms_configfs, \
> > + connectors_group)
> > +
> > #define item_to_config_connector(item) \
> > container_of(to_config_group(item), struct vkms_config_connector, \
> > config_group)
> > @@ -279,4 +286,8 @@ int vkms_enable_writeback_connector(struct vkms_device *vkmsdev,
> > int vkms_init_configfs(void);
> > void vkms_unregister_configfs(void);
> >
> > +/* Connector hotplugging */
> > +enum drm_connector_status vkms_connector_detect(struct drm_connector *connector,
> > + bool force);
> > +
> > #endif /* _VKMS_DRV_H_ */
> > diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c
> > index 0ee1f3f4a305..1a1cd0202c5f 100644
> > --- a/drivers/gpu/drm/vkms/vkms_output.c
> > +++ b/drivers/gpu/drm/vkms/vkms_output.c
> > @@ -1,5 +1,6 @@
> > // SPDX-License-Identifier: GPL-2.0+
> >
> > +#include <drm/drm_print.h>
> > #include <drm/drm_atomic_helper.h>
> > #include <drm/drm_connector.h>
> > #include <drm/drm_crtc.h>
> > @@ -8,10 +9,12 @@
> > #include <drm/drm_plane.h>
> > #include <drm/drm_probe_helper.h>
> > #include <drm/drm_simple_kms_helper.h>
> > +#include <linux/printk.h>
> >
> > #include "vkms_drv.h"
> >
> > static const struct drm_connector_funcs vkms_connector_funcs = {
> > + .detect = vkms_connector_detect,
> > .fill_modes = drm_helper_probe_single_connector_modes,
> > .destroy = drm_connector_cleanup,
> > .reset = drm_atomic_helper_connector_reset,
> > @@ -19,6 +22,48 @@ static const struct drm_connector_funcs vkms_connector_funcs = {
> > .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> > };
> >
> > +static const struct vkms_config_connector *
> > +find_config_for_connector(struct drm_connector *connector)
> > +{
> > + struct vkms_device *vkms = drm_device_to_vkms_device(connector->dev);
> > + struct vkms_configfs *configfs = vkms->configfs;
> > + struct config_item *item;
> > +
> > + if (!configfs) {
> > + pr_info("Default connector has no configfs entry");
> > + return NULL;
> > + }
> > +
> > + list_for_each_entry(item, &configfs->connectors_group.cg_children,
> > + ci_entry) {
> > + struct vkms_config_connector *config_connector =
> > + item_to_config_connector(item);
> > + if (config_connector->connector == connector)
> > + return config_connector;
> > + }
> > +
> > + pr_warn("Could not find config to match connector %s, but configfs was initialized",
> > + connector->name);
> > +
> > + return NULL;
> > +}
> > +
> > +enum drm_connector_status vkms_connector_detect(struct drm_connector *connector,
> > + bool force)
> > +{
> > + enum drm_connector_status status = connector_status_connected;
> > + const struct vkms_config_connector *config_connector =
> > + find_config_for_connector(connector);
> > +
> > + if (!config_connector)
> > + return connector_status_connected;
> > +
> > + if (!config_connector->connected)
> > + status = connector_status_disconnected;
> > +
> > + return status;
> > +}
> > +
> > static const struct drm_encoder_funcs vkms_encoder_funcs = {
> > .destroy = drm_encoder_cleanup,
> > };
> > @@ -280,12 +325,12 @@ int vkms_output_init(struct vkms_device *vkmsdev)
> > struct vkms_config_connector *config_connector =
> > item_to_config_connector(item);
> > struct drm_connector *connector = vkms_connector_init(vkmsdev);
> > -
> > if (IS_ERR(connector)) {
> > DRM_ERROR("Failed to init connector from config: %s",
> > item->ci_name);
> > return PTR_ERR(connector);
> > }
> > + config_connector->connector = connector;
> >
> > for (int j = 0; j < output->num_encoders; j++) {
> > struct encoder_map *encoder = &encoder_map[j];
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