Re: [PATCH v5 02/12] coresight: etm4x: fix underflow for nrseqstate

Leo Yan
2026-04-16T15:11:05Z

On Wed, Apr 15, 2026 at 05:55:18PM +0100, Yeoreum Yun wrote:
> TCRSEQEVR<n> is implemented only when TCRIDR5.NUMSEQSTATE is 0b100,
> in which case n ranges from 0 to 2; otherwise, TCRIDR5.NUMSEQSTATE is 0b000.

My suggestion in previous version is not quite right, thanks for
making this correct.

[...]

> @@ -1395,6 +1395,8 @@ static ssize_t seq_idx_store(struct device *dev,
> struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
> struct etmv4_config *config = &drvdata->config;
>
> + if (!drvdata->nrseqstate)
> + return -EINVAL;

For "nrseqstate = 0" case, would it return -EOPNOTSUPP instead?

Otherwise, LGTM:

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