[PATCH v2 7/9] drm/doc: Relax fdinfo string constraints

Rob Clark
2023-04-27T17:54:57Z

The restriction about no whitespace, etc, really only applies to the
usage of strings in keys. Values can contain anything (other than
newline).

Signed-off-by: Rob Clark <robdclark@chromium.org>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
Documentation/gpu/drm-usage-stats.rst | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst
index bfc14150452c..58dc0d3f8c58 100644
--- a/Documentation/gpu/drm-usage-stats.rst
+++ b/Documentation/gpu/drm-usage-stats.rst
@@ -24,7 +24,7 @@ File format specification
- All keys shall be prefixed with `drm-`.
- Whitespace between the delimiter and first non-whitespace character shall be
ignored when parsing.
-- Neither keys or values are allowed to contain whitespace characters.
+- Keys are not allowed to contain whitespace characters.
- Numerical key value pairs can end with optional unit string.
- Data type of the value is fixed as defined in the specification.

@@ -39,12 +39,13 @@ Data types
----------

- <uint> - Unsigned integer without defining the maximum value.
-- <str> - String excluding any above defined reserved characters or whitespace.
+- <keystr> - String excluding any above defined reserved characters or whitespace.
+- <valstr> - String.

Mandatory fully standardised keys
---------------------------------

-- drm-driver: <str>
+- drm-driver: <valstr>

String shall contain the name this driver registered as via the respective
`struct drm_driver` data structure.
@@ -75,10 +76,10 @@ the above described criteria in order to associate data to individual clients.
Utilization
^^^^^^^^^^^

-- drm-engine-<str>: <uint> ns
+- drm-engine-<keystr>: <uint> ns

GPUs usually contain multiple execution engines. Each shall be given a stable
-and unique name (str), with possible values documented in the driver specific
+and unique name (keystr), with possible values documented in the driver specific
documentation.

Value shall be in specified time units which the respective GPU engine spent
@@ -90,19 +91,19 @@ larger value within a reasonable period. Upon observing a value lower than what
was previously read, userspace is expected to stay with that larger previous
value until a monotonic update is seen.

-- drm-engine-capacity-<str>: <uint>
+- drm-engine-capacity-<keystr>: <uint>

Engine identifier string must be the same as the one specified in the
-drm-engine-<str> tag and shall contain a greater than zero number in case the
+drm-engine-<keystr> tag and shall contain a greater than zero number in case the
exported engine corresponds to a group of identical hardware engines.

In the absence of this tag parser shall assume capacity of one. Zero capacity
is not allowed.

-- drm-cycles-<str>: <uint>
+- drm-cycles-<keystr>: <uint>

Engine identifier string must be the same as the one specified in the
-drm-engine-<str> tag and shall contain the number of busy cycles for the given
+drm-engine-<keystr> tag and shall contain the number of busy cycles for the given
engine.

Values are not required to be constantly monotonic if it makes the driver
@@ -111,12 +112,12 @@ larger value within a reasonable period. Upon observing a value lower than what
was previously read, userspace is expected to stay with that larger previous
value until a monotonic update is seen.

-- drm-maxfreq-<str>: <uint> [Hz|MHz|KHz]
+- drm-maxfreq-<keystr>: <uint> [Hz|MHz|KHz]

Engine identifier string must be the same as the one specified in the
-drm-engine-<str> tag and shall contain the maximum frequency for the given
-engine. Taken together with drm-cycles-<str>, this can be used to calculate
-percentage utilization of the engine, whereas drm-engine-<str> only reflects
+drm-engine-<keystr> tag and shall contain the maximum frequency for the given
+engine. Taken together with drm-cycles-<keystr>, this can be used to calculate
+percentage utilization of the engine, whereas drm-engine-<keystr> only reflects
time active without considering what frequency the engine is operating as a
percentage of it's maximum frequency.

--
2.39.2