[PATCH] perf arm-spe: Don't warn about the discard bit if it doesn't exist

[Leo Yan]

On Fri, Apr 10, 2026 at 12:05:12PM +0100, James Clark wrote:
> Opening an SPE event shows a warning that doesn't concern the user:
> 
>   $ perf record -e arm_spe
>   Unknown/empty format name: discard
> 
> Perf only wants to know if the discard bit is set for configuring the
> event, not in response to anything the user has done. Fix it by adding
> another helper that returns if a config bit exists without warning.
> 
> We should probably keep the warning in evsel__get_config_val() to avoid
> having every caller having to do it, and most format bits should never
> be missing.
> 
> Add a test for the new helper. Rename the parent test function to be
> more generic rather than adding a new one as it requires a lot of
> boilerplate.
> 
> Signed-off-by: James Clark <james.clark at linaro.org>

Reviewed-by: Leo Yan <leo.yan at arm.com>