Re: [PATCH v1 03/11] drm/ras: Introduce set-error-threshold

["Tauro, Riana" <riana.tauro@intel.com>]

On 4/18/2026 2:46 AM, Raag Jadav wrote:
> Add set-error-threshold command support which allows setting threshold
> value of the error. Threshold in RAS context means the number of errors
> the hardware is expected to accumulate before it raises them to software.
> This is to have a fine grained control over error notifications that are
> raised by the hardware.
>
> Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> ---
>   Documentation/gpu/drm-ras.rst            |  9 +++++
>   Documentation/netlink/specs/drm_ras.yaml | 12 ++++++
>   drivers/gpu/drm/drm_ras.c                | 48 ++++++++++++++++++++++++
>   drivers/gpu/drm/drm_ras_nl.c             | 14 +++++++
>   drivers/gpu/drm/drm_ras_nl.h             |  2 +
>   include/drm/drm_ras.h                    | 13 +++++++
>   include/uapi/drm/drm_ras.h               |  1 +
>   7 files changed, 99 insertions(+)
>
> diff --git a/Documentation/gpu/drm-ras.rst b/Documentation/gpu/drm-ras.rst
> index 6443dfd1677f..a819aa150604 100644
> --- a/Documentation/gpu/drm-ras.rst
> +++ b/Documentation/gpu/drm-ras.rst
> @@ -54,6 +54,8 @@ User space tools can:
>     ``node-id`` and ``error-id`` as parameters.
>   * Query specific error threshold value with the ``get-error-threshold`` command, using both
>     ``node-id`` and ``error-id`` as parameters.
> +* Set specific error threshold value with the ``set-error-threshold`` command, using
> +  ``node-id``, ``error-id`` and ``error-threshold`` as parameters.
>   
>   YAML-based Interface
>   --------------------
> @@ -109,3 +111,10 @@ Example: Query threshold value of a given error
>   
>       sudo ynl --family drm_ras --do get-error-threshold --json '{"node-id":0, "error-id":1}'
>       {'error-id': 1, 'error-name': 'error_name1', 'error-threshold': 0}
> +
> +Example: Set threshold value of a given error
> +
> +.. code-block:: bash
> +
> +    sudo ynl --family drm_ras --do set-error-threshold --json '{"node-id":0, "error-id":1, "error-threshold":8}'
> +    None
> diff --git a/Documentation/netlink/specs/drm_ras.yaml b/Documentation/netlink/specs/drm_ras.yaml
> index 95a939fb987d..09824309cdff 100644
> --- a/Documentation/netlink/specs/drm_ras.yaml
> +++ b/Documentation/netlink/specs/drm_ras.yaml
> @@ -150,3 +150,15 @@ operations:
>               - error-id
>               - error-name
>               - error-threshold
> +    -
> +      name: set-error-threshold
> +      doc: >-
> +           Set threshold value of the error.
> +      attribute-set: error-threshold-attrs
> +      flags: [admin-perm]
> +      do:
> +        request:
> +          attributes:
> +            - node-id
> +            - error-id
> +            - error-threshold
> diff --git a/drivers/gpu/drm/drm_ras.c b/drivers/gpu/drm/drm_ras.c
> index d2d853d5d69c..e4ff6d87f824 100644
> --- a/drivers/gpu/drm/drm_ras.c
> +++ b/drivers/gpu/drm/drm_ras.c
> @@ -41,6 +41,9 @@
>    *    Userspace must provide Node ID and Error ID.
>    *    Returns the threshold value of a specific error.
>    *
> + * 4. SET_ERROR_THRESHOLD: Set threshold value of the error.
> + *    Userspace must provide Node ID, Error ID and Threshold value to be set.
> + *
>    * Node registration:
>    *
>    * - drm_ras_node_register(): Registers a new node and assigns
> @@ -72,6 +75,8 @@
>    *   operation, fetching a counter value from a specific node.
>    * - drm_ras_nl_get_error_threshold_doit(): Implements the GET_ERROR_THRESHOLD doit
>    *   operation, fetching the threshold value of a specific error.
> + * - drm_ras_nl_set_error_threshold_doit(): Implements the SET_ERROR_THRESHOLD doit
> + *   operation, setting the threshold value of a specific error.
>    */
>   
>   static DEFINE_XARRAY_ALLOC(drm_ras_xa);
> @@ -184,6 +189,21 @@ static int get_node_error_threshold(u32 node_id, u32 error_id,
>   	return node->query_error_threshold(node, error_id, name, value);
>   }
>   
> +static int set_node_error_threshold(u32 node_id, u32 error_id, u32 value)
> +{
> +	struct drm_ras_node *node;
> +
> +	node = xa_load(&drm_ras_xa, node_id);
> +	if (!node || !node->set_error_threshold)
> +		return -ENOENT;

Use -EOPNOTSUPP for absence of function

> +
> +	if (error_id < node->error_counter_range.first ||
> +	    error_id > node->error_counter_range.last)
> +		return -EINVAL;
> +
> +	return node->set_error_threshold(node, error_id, value);
> +}
> +
>   static int msg_reply_counter_value(struct sk_buff *msg, u32 error_id,
>   				   const char *error_name, u32 value)
>   {
> @@ -417,6 +437,34 @@ int drm_ras_nl_get_error_threshold_doit(struct sk_buff *skb,
>   	return doit_reply_threshold_value(info, node_id, error_id);
>   }
>   
> +/**
> + * drm_ras_nl_set_error_threshold_doit() - Set threshold value of the error
> + * @skb: Netlink message buffer
> + * @info: Generic Netlink info containing attributes of the request
> + *
> + * Extracts the node ID, error ID and threshold value from the netlink attributes
> + * and sets the threshold of the corresponding error.
> + *
> + * Return: 0 on success, or negative errno on failure.
> + */
> +int drm_ras_nl_set_error_threshold_doit(struct sk_buff *skb,
> +				      struct genl_info *info)
> +{
> +	u32 node_id, error_id, value;
> +
> +	if (!info->attrs ||
> +	    GENL_REQ_ATTR_CHECK(info, DRM_RAS_A_ERROR_THRESHOLD_ATTRS_NODE_ID) ||
> +	    GENL_REQ_ATTR_CHECK(info, DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_ID) ||
> +	    GENL_REQ_ATTR_CHECK(info, DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_THRESHOLD))
> +		return -EINVAL;
> +
> +	node_id = nla_get_u32(info->attrs[DRM_RAS_A_ERROR_THRESHOLD_ATTRS_NODE_ID]);
> +	error_id = nla_get_u32(info->attrs[DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_ID]);
> +	value = nla_get_u32(info->attrs[DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_THRESHOLD]);

do we need a check for max threshold here? Probably configured by drivers?
Or is it upto the driver to check? If its upto the driver, please add it 
in the document

Thanks
Riana

> +
> +	return set_node_error_threshold(node_id, error_id, value);
> +}
> +
>   /**
>    * drm_ras_node_register() - Register a new RAS node
>    * @node: Node structure to register
> diff --git a/drivers/gpu/drm/drm_ras_nl.c b/drivers/gpu/drm/drm_ras_nl.c
> index 48e231734f4d..8b202d773dac 100644
> --- a/drivers/gpu/drm/drm_ras_nl.c
> +++ b/drivers/gpu/drm/drm_ras_nl.c
> @@ -28,6 +28,13 @@ static const struct nla_policy drm_ras_get_error_threshold_nl_policy[DRM_RAS_A_E
>   	[DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_ID] = { .type = NLA_U32, },
>   };
>   
> +/* DRM_RAS_CMD_SET_ERROR_THRESHOLD - do */
> +static const struct nla_policy drm_ras_set_error_threshold_nl_policy[DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_THRESHOLD + 1] = {
> +	[DRM_RAS_A_ERROR_THRESHOLD_ATTRS_NODE_ID] = { .type = NLA_U32, },
> +	[DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_ID] = { .type = NLA_U32, },
> +	[DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_THRESHOLD] = { .type = NLA_U32, },
> +};
> +
>   /* Ops table for drm_ras */
>   static const struct genl_split_ops drm_ras_nl_ops[] = {
>   	{
> @@ -56,6 +63,13 @@ static const struct genl_split_ops drm_ras_nl_ops[] = {
>   		.maxattr	= DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_ID,
>   		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
>   	},
> +	{
> +		.cmd		= DRM_RAS_CMD_SET_ERROR_THRESHOLD,
> +		.doit		= drm_ras_nl_set_error_threshold_doit,
> +		.policy		= drm_ras_set_error_threshold_nl_policy,
> +		.maxattr	= DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_THRESHOLD,
> +		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
> +	},
>   };
>   
>   struct genl_family drm_ras_nl_family __ro_after_init = {
> diff --git a/drivers/gpu/drm/drm_ras_nl.h b/drivers/gpu/drm/drm_ras_nl.h
> index 540fe22e2312..9db7f5d00201 100644
> --- a/drivers/gpu/drm/drm_ras_nl.h
> +++ b/drivers/gpu/drm/drm_ras_nl.h
> @@ -20,6 +20,8 @@ int drm_ras_nl_get_error_counter_dumpit(struct sk_buff *skb,
>   					struct netlink_callback *cb);
>   int drm_ras_nl_get_error_threshold_doit(struct sk_buff *skb,
>   					struct genl_info *info);
> +int drm_ras_nl_set_error_threshold_doit(struct sk_buff *skb,
> +					struct genl_info *info);
>   
>   extern struct genl_family drm_ras_nl_family;
>   
> diff --git a/include/drm/drm_ras.h b/include/drm/drm_ras.h
> index 50cee70bd065..7a69821b8b78 100644
> --- a/include/drm/drm_ras.h
> +++ b/include/drm/drm_ras.h
> @@ -71,6 +71,19 @@ struct drm_ras_node {
>   	 */
>   	int (*query_error_threshold)(struct drm_ras_node *node, u32 error_id,
>   				     const char **name, u32 *val);
> +	/**
> +	 * @set_error_threshold:
> +	 *
> +	 * This callback is used by drm-ras to set threshold value of a specific
> +	 * error.
> +	 *
> +	 * Driver should expect set_error_threshold() to be called with error_id
> +	 * from `error_counter_range.first` to `error_counter_range.last`.
> +	 *
> +	 * Returns: 0 on success, negative error code on failure.
> +	 */
> +	int (*set_error_threshold)(struct drm_ras_node *node, u32 error_id,
> +				   u32 val);
>   
>   	/** @priv: Driver private data */
>   	void *priv;
> diff --git a/include/uapi/drm/drm_ras.h b/include/uapi/drm/drm_ras.h
> index 49c5ca497d73..8ff0311d0d63 100644
> --- a/include/uapi/drm/drm_ras.h
> +++ b/include/uapi/drm/drm_ras.h
> @@ -52,6 +52,7 @@ enum {
>   	DRM_RAS_CMD_LIST_NODES = 1,
>   	DRM_RAS_CMD_GET_ERROR_COUNTER,
>   	DRM_RAS_CMD_GET_ERROR_THRESHOLD,
> +	DRM_RAS_CMD_SET_ERROR_THRESHOLD,
>   
>   	__DRM_RAS_CMD_MAX,
>   	DRM_RAS_CMD_MAX = (__DRM_RAS_CMD_MAX - 1)