Re: [PATCH 01/11] coresight-etm4x: Adding CoreSight ETM4x driver

From: Linus Walleij
Date: Tue Apr 28 2015 - 08:28:32 EST

On Thu, Apr 23, 2015 at 12:40 AM, Mathieu Poirier
<mathieu.poirier@xxxxxxxxxx> wrote:

> From: Pratik Patel <pratikp@xxxxxxxxxxxxxx>
> This driver manages the CoreSight ETMv4 (Embedded Trace Macrocell) IP block
> to support HW assisted tracing on ARMv7 and ARMv8 architectures.
> Signed-off-by: Pratik Patel <pratikp@xxxxxxxxxxxxxx>
> Signed-off-by: Kaixu Xia <xiakaixu@xxxxxxxxxx>
> Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>

> +/* The number of ETMv4 currently registered */
> +static int etm4_count;
> +static struct etmv4_drvdata *etmdrvdata[NR_CPUS];

Don't you need a mutex or something around etm4_count so
as to protect it? You could also make it an atomic.

Also why is it a signed int ... unsigned int?

I know, lame comments, the runtime PM stuff looks perfect now,
someone had a refcount comment but it's doing the right thing.

Linus Walleij
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at