[PATCH v2] drm: use ida to allocate connector ids
Ilia Mirkin
imirkin at alum.mit.edu
Wed Aug 7 01:28:35 PDT 2013
On Wed, Aug 7, 2013 at 4:00 AM, Ville Syrjälä
<ville.syrjala at linux.intel.com> wrote:
> 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.
I assume this is in reference to the drm_mode_object_get above? I just
noticed that... or was there something else too?
>
> 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.
OK, I'm not really sure what the whole drm locking situation is. If
it's OK to do a GFP_KERNEL alloc inside the "big kms lock" (BKL v2?),
I might as well use the ida_simple_get interface.
>
>> 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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