None of our wrappers around container_of to access our objects from the
DRM object pointer actually modify the latter.
Let's make them const.
Signed-off-by: Maxime Ripard <[email protected]>
---
drivers/gpu/drm/vc4/vc4_hdmi.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h
index dc3ccd8002a0..023ea64ef006 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.h
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
@@ -224,13 +224,13 @@ struct vc4_hdmi {
};
static inline struct vc4_hdmi *
-connector_to_vc4_hdmi(struct drm_connector *connector)
+connector_to_vc4_hdmi(const struct drm_connector *connector)
{
return container_of(connector, struct vc4_hdmi, connector);
}
static inline struct vc4_hdmi *
-encoder_to_vc4_hdmi(struct drm_encoder *encoder)
+encoder_to_vc4_hdmi(const struct drm_encoder *encoder)
{
struct vc4_encoder *_encoder = to_vc4_encoder(encoder);
return container_of(_encoder, struct vc4_hdmi, encoder);
@@ -244,7 +244,7 @@ struct vc4_hdmi_connector_state {
};
static inline struct vc4_hdmi_connector_state *
-conn_state_to_vc4_hdmi_conn_state(struct drm_connector_state *conn_state)
+conn_state_to_vc4_hdmi_conn_state(const struct drm_connector_state *conn_state)
{
return container_of(conn_state, struct vc4_hdmi_connector_state, base);
}
--
2.38.1
On Wed, 11 Jan 2023, Thomas Zimmermann <[email protected]> wrote:
> Hi
>
> Am 07.12.22 um 17:07 schrieb Maxime Ripard:
>> None of our wrappers around container_of to access our objects from the
>> DRM object pointer actually modify the latter.
>>
>> Let's make them const.
>>
>> Signed-off-by: Maxime Ripard <[email protected]>
>
> Personally, I wouldn't take this patch as it does an implicit const cast
> on the pointer.
>
> For const correctness, it seems better to add new helpers that keep the
> const. Those could be use in places where the caller is not allowed to
> modify the state (i.e., atomic_update, et al).
>
> Something like this:
>
> const struct vc4_hdmi *
> const_connector_to_vc4_hdmi(const struct drm_connector *connector)
> {
> return container_of(connector, const struct vc4_hdmi,
> connector);
> }
See container_of_const().
BR,
Jani.
>
> Best regards
> Thomas
>
>> ---
>> drivers/gpu/drm/vc4/vc4_hdmi.h | 6 +++---
>> 1 file changed, 3 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h
>> index dc3ccd8002a0..023ea64ef006 100644
>> --- a/drivers/gpu/drm/vc4/vc4_hdmi.h
>> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
>> @@ -224,13 +224,13 @@ struct vc4_hdmi {
>> };
>>
>> static inline struct vc4_hdmi *
>> -connector_to_vc4_hdmi(struct drm_connector *connector)
>> +connector_to_vc4_hdmi(const struct drm_connector *connector)
>> {
>> return container_of(connector, struct vc4_hdmi, connector);
>> }
>>
>> static inline struct vc4_hdmi *
>> -encoder_to_vc4_hdmi(struct drm_encoder *encoder)
>> +encoder_to_vc4_hdmi(const struct drm_encoder *encoder)
>> {
>> struct vc4_encoder *_encoder = to_vc4_encoder(encoder);
>> return container_of(_encoder, struct vc4_hdmi, encoder);
>> @@ -244,7 +244,7 @@ struct vc4_hdmi_connector_state {
>> };
>>
>> static inline struct vc4_hdmi_connector_state *
>> -conn_state_to_vc4_hdmi_conn_state(struct drm_connector_state *conn_state)
>> +conn_state_to_vc4_hdmi_conn_state(const struct drm_connector_state *conn_state)
>> {
>> return container_of(conn_state, struct vc4_hdmi_connector_state, base);
>> }
>>
--
Jani Nikula, Intel Open Source Graphics Center
Hi
Am 07.12.22 um 17:07 schrieb Maxime Ripard:
> None of our wrappers around container_of to access our objects from the
> DRM object pointer actually modify the latter.
>
> Let's make them const.
>
> Signed-off-by: Maxime Ripard <[email protected]>
Personally, I wouldn't take this patch as it does an implicit const cast
on the pointer.
For const correctness, it seems better to add new helpers that keep the
const. Those could be use in places where the caller is not allowed to
modify the state (i.e., atomic_update, et al).
Something like this:
const struct vc4_hdmi *
const_connector_to_vc4_hdmi(const struct drm_connector *connector)
{
return container_of(connector, const struct vc4_hdmi,
connector);
}
Best regards
Thomas
> ---
> drivers/gpu/drm/vc4/vc4_hdmi.h | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.h b/drivers/gpu/drm/vc4/vc4_hdmi.h
> index dc3ccd8002a0..023ea64ef006 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.h
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.h
> @@ -224,13 +224,13 @@ struct vc4_hdmi {
> };
>
> static inline struct vc4_hdmi *
> -connector_to_vc4_hdmi(struct drm_connector *connector)
> +connector_to_vc4_hdmi(const struct drm_connector *connector)
> {
> return container_of(connector, struct vc4_hdmi, connector);
> }
>
> static inline struct vc4_hdmi *
> -encoder_to_vc4_hdmi(struct drm_encoder *encoder)
> +encoder_to_vc4_hdmi(const struct drm_encoder *encoder)
> {
> struct vc4_encoder *_encoder = to_vc4_encoder(encoder);
> return container_of(_encoder, struct vc4_hdmi, encoder);
> @@ -244,7 +244,7 @@ struct vc4_hdmi_connector_state {
> };
>
> static inline struct vc4_hdmi_connector_state *
> -conn_state_to_vc4_hdmi_conn_state(struct drm_connector_state *conn_state)
> +conn_state_to_vc4_hdmi_conn_state(const struct drm_connector_state *conn_state)
> {
> return container_of(conn_state, struct vc4_hdmi_connector_state, base);
> }
>
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev