[PATCH v6 20/25] coresight: cti: don't disable ect device if it's not enabled

[Mike Leach]

Hi Tingwei,

On Fri, 31 Jul 2020 at 07:42, Tingwei Zhang <tingwei at codeaurora.org> wrote:
>
> If associated ect device is not enabled at first place, disable
> routine should not be called. Add ect_enabled flag to check whether
> ect device is enabled. Fix the issue in below case.  Ect device is
> not available when associated coresight device enabled and the
> association is established after coresight device is enabled.
>
> Signed-off-by: Mike Leach <mike.leach at linaro.org>
> Signed-off-by: Tingwei Zhang <tingwei at codeaurora.org>
> ---
>  drivers/hwtracing/coresight/coresight.c | 11 ++++++++---
>  include/linux/coresight.h               |  1 +
>  2 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
> index 8b55383cfcf1..83a46cf37968 100644
> --- a/drivers/hwtracing/coresight/coresight.c
> +++ b/drivers/hwtracing/coresight/coresight.c
> @@ -245,13 +245,18 @@ coresight_control_assoc_ectdev(struct coresight_device *csdev, bool enable)
>
>         if (!ect_csdev)
>                 return 0;
> +       if ((!ect_ops(ect_csdev)->enable) || (!ect_ops(ect_csdev)->disable))
> +               return 0;
>
>         if (enable) {
> -               if (ect_ops(ect_csdev)->enable)
> -                       ect_ret = ect_ops(ect_csdev)->enable(ect_csdev);
> +               ect_ret = ect_ops(ect_csdev)->enable(ect_csdev);
> +               if (ect_ret)

Should this be:-
if (!ect_ret)

However, this problem is corrected in the next patch - so the set as
tested overall works.

This needs fixing or it might be better to combine this patch and the
next patch into a single patch?
Both are required because the CTI can be loaded as a module. Both
adjust the same block of functionality.

Mathieu may have a view on the best solution option here.

Mike



> +                       csdev->ect_enabled = true;
>         } else {
> -               if (ect_ops(ect_csdev)->disable)
> +               if (csdev->ect_enabled) {
>                         ect_ret = ect_ops(ect_csdev)->disable(ect_csdev);
> +                       csdev->ect_enabled = false;
> +               }
>         }
>
>         /* output warning if ECT enable is preventing trace operation */
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index 3bb738f9a326..7d3c87e5b97c 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -208,6 +208,7 @@ struct coresight_device {
>         /* sysfs links between components */
>         int nr_links;
>         bool has_conns_grp;
> +       bool ect_enabled; /* true only if associated ect device is enabled */
>  };
>
>  /*
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>


--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK