Re: [PATCH v1 02/11] drm/ras: Introduce get-error-threshold

Tauro, Riana
2026-04-22T05:49:58Z

On 4/18/2026 2:46 AM, Raag Jadav wrote:
> Add get-error-threshold command support which allows querying 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 | 8 ++
> Documentation/netlink/specs/drm_ras.yaml | 37 ++++++++
> drivers/gpu/drm/drm_ras.c | 103 +++++++++++++++++++++++
> drivers/gpu/drm/drm_ras_nl.c | 13 +++
> drivers/gpu/drm/drm_ras_nl.h | 2 +
> include/drm/drm_ras.h | 14 +++
> include/uapi/drm/drm_ras.h | 11 +++
> 7 files changed, 188 insertions(+)
>
> diff --git a/Documentation/gpu/drm-ras.rst b/Documentation/gpu/drm-ras.rst
> index 70b246a78fc8..6443dfd1677f 100644
> --- a/Documentation/gpu/drm-ras.rst
> +++ b/Documentation/gpu/drm-ras.rst
> @@ -52,6 +52,8 @@ User space tools can:
> as a parameter.
> * Query specific error counter values with the ``get-error-counter`` command, using both
> ``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.
Also define what is a thresold. How can it be used?
>
> YAML-based Interface
> --------------------
> @@ -101,3 +103,9 @@ Example: Query an error counter for a given node
> sudo ynl --family drm_ras --do get-error-counter --json '{"node-id":0, "error-id":1}'
> {'error-id': 1, 'error-name': 'error_name1', 'error-value': 0}
>
> +Example: Query threshold value of a given error
> +
> +.. code-block:: bash
> +
> + 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}
> diff --git a/Documentation/netlink/specs/drm_ras.yaml b/Documentation/netlink/specs/drm_ras.yaml
> index 79af25dac3c5..95a939fb987d 100644
> --- a/Documentation/netlink/specs/drm_ras.yaml
> +++ b/Documentation/netlink/specs/drm_ras.yaml
> @@ -69,6 +69,25 @@ attribute-sets:
> name: error-value
> type: u32
> doc: Current value of the requested error counter.
> + -
> + name: error-threshold-attrs
> + attributes:
> + -
> + name: node-id
> + type: u32
> + doc: Node ID targeted by this operation.
> + -
> + name: error-id
> + type: u32
> + doc: Unique identifier for a specific error within the node.
> + -
> + name: error-name
> + type: string
> + doc: Name of the error.
> + -
> + name: error-threshold
> + type: u32
> + doc: Threshold value of the error.
>
> operations:
> list:
> @@ -113,3 +132,21 @@ operations:
> - node-id
> reply:
> attributes: *errorinfo
> + -
> + name: get-error-threshold
> + doc: >-
> + Retrieve threshold value of the error.
> + The response includes the id, the name, and current threshold
> + value of the error.
> + attribute-set: error-threshold-attrs
> + flags: [admin-perm]
> + do:
> + request:
> + attributes:
> + - node-id
> + - error-id
> + reply:
> + attributes:
> + - error-id
> + - error-name
> + - error-threshold
> diff --git a/drivers/gpu/drm/drm_ras.c b/drivers/gpu/drm/drm_ras.c
> index 1f7435d60f11..d2d853d5d69c 100644
> --- a/drivers/gpu/drm/drm_ras.c
> +++ b/drivers/gpu/drm/drm_ras.c
> @@ -37,6 +37,10 @@
> * Returns all counters of a node if only Node ID is provided or specific
> * error counters.
> *
> + * 3. GET_ERROR_THRESHOLD: Query threshold value of the error.
> + * Userspace must provide Node ID and Error ID.
> + * Returns the threshold value of a specific error.
> + *
> * Node registration:
> *
> * - drm_ras_node_register(): Registers a new node and assigns
> @@ -66,6 +70,8 @@
> * operation, fetching all counters from a specific node.
> * - drm_ras_nl_get_error_counter_doit(): Implements the GET_ERROR_COUNTER doit
> * 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.
> */
>
> static DEFINE_XARRAY_ALLOC(drm_ras_xa);
> @@ -162,6 +168,22 @@ static int get_node_error_counter(u32 node_id, u32 error_id,
> return node->query_error_counter(node, error_id, name, value);
> }
>
> +static int get_node_error_threshold(u32 node_id, u32 error_id,
> + const char **name, u32 *value)
> +{
> + struct drm_ras_node *node;
> +
> + node = xa_load(&drm_ras_xa, node_id);
> + if (!node || !node->query_error_threshold)
> + return -ENOENT;

For the absence of the function, return -EOPNOTSUPP

> +
> + if (error_id < node->error_counter_range.first ||
> + error_id > node->error_counter_range.last)
> + return -EINVAL;
> +
> + return node->query_error_threshold(node, error_id, name, value);
> +}
> +
> static int msg_reply_counter_value(struct sk_buff *msg, u32 error_id,
> const char *error_name, u32 value)
> {
> @@ -180,6 +202,24 @@ static int msg_reply_counter_value(struct sk_buff *msg, u32 error_id,
> value);
> }
>
> +static int msg_reply_threshold_value(struct sk_buff *msg, u32 error_id,
> + const char *error_name, u32 value)
> +{
> + int ret;
> +
> + ret = nla_put_u32(msg, DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_ID, error_id);
> + if (ret)
> + return ret;
> +
> + ret = nla_put_string(msg, DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_NAME,
> + error_name);
> + if (ret)
> + return ret;
> +
> + return nla_put_u32(msg, DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_THRESHOLD,
> + value);
> +}
> +
> static int doit_reply_counter_value(struct genl_info *info, u32 node_id,
> u32 error_id)
> {
> @@ -216,6 +256,42 @@ static int doit_reply_counter_value(struct genl_info *info, u32 node_id,
> return genlmsg_reply(msg, info);
> }
>
> +static int doit_reply_threshold_value(struct genl_info *info, u32 node_id,
> + u32 error_id)
> +{
> + struct sk_buff *msg;
> + struct nlattr *hdr;
> + const char *error_name;
> + u32 value;
> + int ret;
> +
> + msg = genlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + hdr = genlmsg_iput(msg, info);
> + if (!hdr) {
> + nlmsg_free(msg);
> + return -EMSGSIZE;
> + }
> +
> + ret = get_node_error_threshold(node_id, error_id,
> + &error_name, &value);
> + if (ret)
> + return ret;

You have to cancel and free genlmsg here.
Looks like the counter patch also has the same issue. Will send out a fix.

> +
> + ret = msg_reply_threshold_value(msg, error_id, error_name, value);
> + if (ret) {
> + genlmsg_cancel(msg, hdr);
> + nlmsg_free(msg);
> + return ret;
> + }
> +
> + genlmsg_end(msg, hdr);
> +
> + return genlmsg_reply(msg, info);
> +}
> +
> /**
> * drm_ras_nl_get_error_counter_dumpit() - Dump all Error Counters
> * @skb: Netlink message buffer
> @@ -314,6 +390,33 @@ int drm_ras_nl_get_error_counter_doit(struct sk_buff *skb,
> return doit_reply_counter_value(info, node_id, error_id);
> }
>
> +/**
> + * drm_ras_nl_get_error_threshold_doit() - Query threshold value of the error
Nit: an

Thanks
Riana
> + * @skb: Netlink message buffer
> + * @info: Generic Netlink info containing attributes of the request
> + *
> + * Extracts the node ID and error ID from the netlink attributes and
> + * retrieves the current threshold of the corresponding error. Sends the
> + * result back to the requesting user via the standard Genl reply.
> + *
> + * Return: 0 on success, or negative errno on failure.
> + */
> +int drm_ras_nl_get_error_threshold_doit(struct sk_buff *skb,
> + struct genl_info *info)
> +{
> + u32 node_id, error_id;
> +
> + 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))
> + 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]);
> +
> + return doit_reply_threshold_value(info, node_id, error_id);
> +}
> +
> /**
> * 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 16803d0c4a44..48e231734f4d 100644
> --- a/drivers/gpu/drm/drm_ras_nl.c
> +++ b/drivers/gpu/drm/drm_ras_nl.c
> @@ -22,6 +22,12 @@ static const struct nla_policy drm_ras_get_error_counter_dump_nl_policy[DRM_RAS_
> [DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID] = { .type = NLA_U32, },
> };
>
> +/* DRM_RAS_CMD_GET_ERROR_THRESHOLD - do */
> +static const struct nla_policy drm_ras_get_error_threshold_nl_policy[DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_ID + 1] = {
> + [DRM_RAS_A_ERROR_THRESHOLD_ATTRS_NODE_ID] = { .type = NLA_U32, },
> + [DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_ID] = { .type = NLA_U32, },
> +};
> +
> /* Ops table for drm_ras */
> static const struct genl_split_ops drm_ras_nl_ops[] = {
> {
> @@ -43,6 +49,13 @@ static const struct genl_split_ops drm_ras_nl_ops[] = {
> .maxattr = DRM_RAS_A_ERROR_COUNTER_ATTRS_NODE_ID,
> .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DUMP,
> },
> + {
> + .cmd = DRM_RAS_CMD_GET_ERROR_THRESHOLD,
> + .doit = drm_ras_nl_get_error_threshold_doit,
> + .policy = drm_ras_get_error_threshold_nl_policy,
> + .maxattr = DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_ID,
> + .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 06ccd9342773..540fe22e2312 100644
> --- a/drivers/gpu/drm/drm_ras_nl.h
> +++ b/drivers/gpu/drm/drm_ras_nl.h
> @@ -18,6 +18,8 @@ int drm_ras_nl_get_error_counter_doit(struct sk_buff *skb,
> struct genl_info *info);
> 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);
>
> extern struct genl_family drm_ras_nl_family;
>
> diff --git a/include/drm/drm_ras.h b/include/drm/drm_ras.h
> index 5d50209e51db..50cee70bd065 100644
> --- a/include/drm/drm_ras.h
> +++ b/include/drm/drm_ras.h
> @@ -57,6 +57,20 @@ struct drm_ras_node {
> */
> int (*query_error_counter)(struct drm_ras_node *node, u32 error_id,
> const char **name, u32 *val);
> + /**
> + * @query_error_threshold:
> + *
> + * This callback is used by drm-ras to query threshold value of a
> + * specific error.
> + *
> + * Driver should expect query_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 (*query_error_threshold)(struct drm_ras_node *node, u32 error_id,
> + const char **name, 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 5f40fa5b869d..49c5ca497d73 100644
> --- a/include/uapi/drm/drm_ras.h
> +++ b/include/uapi/drm/drm_ras.h
> @@ -38,9 +38,20 @@ enum {
> DRM_RAS_A_ERROR_COUNTER_ATTRS_MAX = (__DRM_RAS_A_ERROR_COUNTER_ATTRS_MAX - 1)
> };
>
> +enum {
> + DRM_RAS_A_ERROR_THRESHOLD_ATTRS_NODE_ID = 1,
> + DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_ID,
> + DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_NAME,
> + DRM_RAS_A_ERROR_THRESHOLD_ATTRS_ERROR_THRESHOLD,
> +
> + __DRM_RAS_A_ERROR_THRESHOLD_ATTRS_MAX,
> + DRM_RAS_A_ERROR_THRESHOLD_ATTRS_MAX = (__DRM_RAS_A_ERROR_THRESHOLD_ATTRS_MAX - 1)
> +};
> +
> enum {
> DRM_RAS_CMD_LIST_NODES = 1,
> DRM_RAS_CMD_GET_ERROR_COUNTER,
> + DRM_RAS_CMD_GET_ERROR_THRESHOLD,
>
> __DRM_RAS_CMD_MAX,
> DRM_RAS_CMD_MAX = (__DRM_RAS_CMD_MAX - 1)