[PATCH] coresight: etb10: Fix check for bogus buffer depth

[Mathieu Poirier]

On 8 April 2015 at 16:47, Mark Brown <broonie at kernel.org> wrote:
> We attempt to sanity check the buffer depth reported by the hardware by
> making sure it is not less than zero however this check will never be true
> since the buffer depth is stored in an unsigned integer. Instead change
> the check to look for the top bit being set which was the intention.
>
> Signed-off-by: Mark Brown <broonie at kernel.org>
> ---
>
> This depends on the patch I sent earlier today for context though
> there's no direct dependency (and this check isn't sufficient to catch
> the fault I'm seeing).
>
>  drivers/hwtracing/coresight/coresight-etb10.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
> index 46eb9f88a29f..2a77d83130e6 100644
> --- a/drivers/hwtracing/coresight/coresight-etb10.c
> +++ b/drivers/hwtracing/coresight/coresight-etb10.c
> @@ -457,7 +457,7 @@ static int etb_probe(struct amba_device *adev, const struct amba_id *id)
>         drvdata->buffer_depth = etb_get_buffer_depth(drvdata);
>         clk_disable_unprepare(drvdata->clk);
>
> -       if (drvdata->buffer_depth < 0)
> +       if (drvdata->buffer_depth & 0x80000000)
>                 return -EINVAL;
>
>         drvdata->buf = devm_kzalloc(dev,
> --
> 2.1.4
>

Good catch - applied.

Thanks,
Mathieu