[PATCH v2] drm: use ida to allocate connector ids
Ville Syrjälä
ville.syrjala at linux.intel.com
Wed Aug 7 01:00:14 PDT 2013
On Tue, Jul 30, 2013 at 03:51:49AM -0400, Ilia Mirkin wrote:
> This makes it so that reloading a module does not cause all the
> connector ids to change, which are user-visible and sometimes used
> for configuration.
>
> Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
> ---
>
> v1 -> v2: correct loop condition... not sure how that slipped past
> me... the code started out by being <= DRM...VIRTUAL, I guess
>
> drivers/gpu/drm/drm_crtc.c | 61 +++++++++++++++++++++++++++++++---------------
> drivers/gpu/drm/drm_drv.c | 2 ++
> include/drm/drm_crtc.h | 2 ++
> 3 files changed, 46 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index fc83bb9..ed7599a 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -186,29 +186,29 @@ static const struct drm_prop_enum_list drm_dirty_info_enum_list[] = {
> struct drm_conn_prop_enum_list {
> int type;
> const char *name;
> - int count;
> + struct ida count;
I'd rename this to something else. 'count' is just confusing.
> };
>
> /*
> * Connector and encoder types.
> */
> static struct drm_conn_prop_enum_list drm_connector_enum_list[] =
> -{ { DRM_MODE_CONNECTOR_Unknown, "Unknown", 0 },
> - { DRM_MODE_CONNECTOR_VGA, "VGA", 0 },
> - { DRM_MODE_CONNECTOR_DVII, "DVI-I", 0 },
> - { DRM_MODE_CONNECTOR_DVID, "DVI-D", 0 },
> - { DRM_MODE_CONNECTOR_DVIA, "DVI-A", 0 },
> - { DRM_MODE_CONNECTOR_Composite, "Composite", 0 },
> - { DRM_MODE_CONNECTOR_SVIDEO, "SVIDEO", 0 },
> - { DRM_MODE_CONNECTOR_LVDS, "LVDS", 0 },
> - { DRM_MODE_CONNECTOR_Component, "Component", 0 },
> - { DRM_MODE_CONNECTOR_9PinDIN, "DIN", 0 },
> - { DRM_MODE_CONNECTOR_DisplayPort, "DP", 0 },
> - { DRM_MODE_CONNECTOR_HDMIA, "HDMI-A", 0 },
> - { DRM_MODE_CONNECTOR_HDMIB, "HDMI-B", 0 },
> - { DRM_MODE_CONNECTOR_TV, "TV", 0 },
> - { DRM_MODE_CONNECTOR_eDP, "eDP", 0 },
> - { DRM_MODE_CONNECTOR_VIRTUAL, "Virtual", 0},
> +{ { DRM_MODE_CONNECTOR_Unknown, "Unknown" },
> + { DRM_MODE_CONNECTOR_VGA, "VGA" },
> + { DRM_MODE_CONNECTOR_DVII, "DVI-I" },
> + { DRM_MODE_CONNECTOR_DVID, "DVI-D" },
> + { DRM_MODE_CONNECTOR_DVIA, "DVI-A" },
> + { DRM_MODE_CONNECTOR_Composite, "Composite" },
> + { DRM_MODE_CONNECTOR_SVIDEO, "SVIDEO" },
> + { DRM_MODE_CONNECTOR_LVDS, "LVDS" },
> + { DRM_MODE_CONNECTOR_Component, "Component" },
> + { DRM_MODE_CONNECTOR_9PinDIN, "DIN" },
> + { DRM_MODE_CONNECTOR_DisplayPort, "DP" },
> + { DRM_MODE_CONNECTOR_HDMIA, "HDMI-A" },
> + { DRM_MODE_CONNECTOR_HDMIB, "HDMI-B" },
> + { DRM_MODE_CONNECTOR_TV, "TV" },
> + { DRM_MODE_CONNECTOR_eDP, "eDP" },
> + { DRM_MODE_CONNECTOR_VIRTUAL, "Virtual" },
> };
>
> static const struct drm_prop_enum_list drm_encoder_enum_list[] =
> @@ -220,6 +220,22 @@ static const struct drm_prop_enum_list drm_encoder_enum_list[] =
> { DRM_MODE_ENCODER_VIRTUAL, "Virtual" },
> };
>
> +void drm_connector_ida_init(void)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(drm_connector_enum_list); i++)
> + ida_init(&drm_connector_enum_list[i].count);
> +}
> +
> +void drm_connector_ida_destroy(void)
> +{
> + int i;
> +
> + for (i = 0; i < ARRAY_SIZE(drm_connector_enum_list); i++)
> + ida_destroy(&drm_connector_enum_list[i].count);
> +}
> +
> const char *drm_get_encoder_name(const struct drm_encoder *encoder)
> {
> static char buf[32];
> @@ -711,6 +727,9 @@ int drm_connector_init(struct drm_device *dev,
> int connector_type)
> {
> int ret;
> + struct ida *count = &drm_connector_enum_list[connector_type].count;
> +
> + ida_pre_get(count, GFP_KERNEL);
>
> drm_modeset_lock_all(dev);
>
> @@ -722,8 +741,9 @@ int drm_connector_init(struct drm_device *dev,
> connector->dev = dev;
> connector->funcs = funcs;
> connector->connector_type = connector_type;
> - connector->connector_type_id =
> - ++drm_connector_enum_list[connector_type].count; /* TODO */
> + ret = ida_get_new_above(count, 1, &connector->connector_type_id);
> + if (ret)
> + goto out;
Leak.
Also there's no retry loop w/ ida_pre_get() and since that's outside the
big kms lock, there could be a (small) chance that someone else already
consumed the allocation done in ida_pre_get(). And then we'll return
-EAGAIN which is a rather confusing error from an init function. I
guess you could just move the ida_pre_get() inside the kms lock and
avoid that race.
> INIT_LIST_HEAD(&connector->probed_modes);
> INIT_LIST_HEAD(&connector->modes);
> connector->edid_blob_ptr = NULL;
> @@ -764,6 +784,9 @@ void drm_connector_cleanup(struct drm_connector *connector)
> list_for_each_entry_safe(mode, t, &connector->modes, head)
> drm_mode_remove(connector, mode);
>
> + ida_remove(&drm_connector_enum_list[connector->connector_type].count,
> + connector->connector_type_id);
> +
> drm_mode_object_put(dev, &connector->base);
> list_del(&connector->head);
> dev->mode_config.num_connector--;
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 99fcd7c..00597a1 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -251,6 +251,7 @@ static int __init drm_core_init(void)
> int ret = -ENOMEM;
>
> drm_global_init();
> + drm_connector_ida_init();
> idr_init(&drm_minors_idr);
>
> if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
> @@ -298,6 +299,7 @@ static void __exit drm_core_exit(void)
>
> unregister_chrdev(DRM_MAJOR, "drm");
>
> + drm_connector_ida_destroy();
> idr_destroy(&drm_minors_idr);
> }
>
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index fa12a2f..effee9d 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -869,6 +869,8 @@ extern int drm_crtc_init(struct drm_device *dev,
> const struct drm_crtc_funcs *funcs);
> extern void drm_crtc_cleanup(struct drm_crtc *crtc);
>
> +extern void drm_connector_ida_init(void);
> +extern void drm_connector_ida_destroy(void);
> extern int drm_connector_init(struct drm_device *dev,
> struct drm_connector *connector,
> const struct drm_connector_funcs *funcs,
> --
> 1.8.1.5
>
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--
Ville Syrjälä
Intel OTC
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