Re: [PATCH] [Patch v3]Add ETE devarch condition in etm4_init_iomem_access

[Mike Leach]

Hi,

Please stop using the unusual title format of [PATCH}[Patch v3] - use
the git command line options to ensure the format is e.g. [PATCH v3]

What is the reason that your device cannot use the system instructions
to access the ETE? Using a memory interface, if implemented, is only
recommended for external debuggers, or on systems where the
implementation of system register access is not working.

On Thu, 10 Apr 2025 at 10:52, yiru zhang <yiru.zhang@xxxxxxxxxxxx> wrote:
>
> Due to ETE supported, so add ETE devarch condition in etm4_init_iomem_access.
>
> Signed-off-by: yiru zhang <yiru.zhang@xxxxxxxxxxxx>
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-kbuild-all/202504101759.7Ls0Uy4o-lkp@xxxxxxxxx/
>
> v1->v2: use switch case way
> v2->v3: clean build warning
> ---
>  drivers/hwtracing/coresight/coresight-etm4x-core.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index 2b8f10463840..4002a2823fd0 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -1135,11 +1135,15 @@ static bool etm4_init_iomem_access(struct etmv4_drvdata *drvdata,
>          * with MMIO. But we cannot touch the OSLK until we are
>          * sure this is an ETM. So rely only on the TRCDEVARCH.
>          */
> -       if ((devarch & ETM_DEVARCH_ID_MASK) != ETM_DEVARCH_ETMv4x_ARCH) {
> -               pr_warn_once("TRCDEVARCH doesn't match ETMv4 architecture\n");
> +       switch (devarch & ETM_DEVARCH_ID_MASK) {
> +       case ETM_DEVARCH_ETMv4x_ARCH:
> +       case ETM_DEVARCH_ETE_ARCH:
> +               break;
> +       default:
> +               pr_warn_once("Unknown ETM architecture: 0x%lx\n",
> +                            devarch & ETM_DEVARCH_ID_MASK);
>                 return false;
>         }
> -
>         drvdata->arch = etm_devarch_to_arch(devarch);
>         *csa = CSDEV_ACCESS_IOMEM(drvdata->base);
>         return true;
> --
> 2.46.0
>

Otherwise -

Reviewed-by: Mike Leach <mike.leach@xxxxxxxxxx>
-- 
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK