On Wed, Jan 09, 2019 at 11:16:48PM +0530, Sai Prakash Ranjan wrote:
> SDM845 has ETMv4.2 and can use the existing etm4x driver.
> But the current etm driver checks only for ETMv4.0 and
> errors out for other etm4x versions. This patch adds this
> missing support to enable SoC's with ETMv4x to use same
> driver by checking only the ETM architecture major version
> number.
>
> Without this change, we get below error during etm probe:
>
> / # dmesg | grep etm
> [ 6.660093] coresight-etm4x: probe of 7040000.etm failed with error -22
> [ 6.666902] coresight-etm4x: probe of 7140000.etm failed with error -22
> [ 6.673708] coresight-etm4x: probe of 7240000.etm failed with error -22
> [ 6.680511] coresight-etm4x: probe of 7340000.etm failed with error -22
> [ 6.687313] coresight-etm4x: probe of 7440000.etm failed with error -22
> [ 6.694113] coresight-etm4x: probe of 7540000.etm failed with error -22
> [ 6.700914] coresight-etm4x: probe of 7640000.etm failed with error -22
> [ 6.707717] coresight-etm4x: probe of 7740000.etm failed with error -22
>
> With this change, etm probe is successful:
>
> / # dmesg | grep coresight
> [ 6.659198] coresight-etm4x 7040000.etm: CPU0: ETM v4.2 initialized
> [ 6.665848] coresight-etm4x 7140000.etm: CPU1: ETM v4.2 initialized
> [ 6.672493] coresight-etm4x 7240000.etm: CPU2: ETM v4.2 initialized
> [ 6.679129] coresight-etm4x 7340000.etm: CPU3: ETM v4.2 initialized
> [ 6.685770] coresight-etm4x 7440000.etm: CPU4: ETM v4.2 initialized
> [ 6.692403] coresight-etm4x 7540000.etm: CPU5: ETM v4.2 initialized
> [ 6.699024] coresight-etm4x 7640000.etm: CPU6: ETM v4.2 initialized
> [ 6.705646] coresight-etm4x 7740000.etm: CPU7: ETM v4.2 initialized
>
> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
> ---
> drivers/hwtracing/coresight/coresight-etm4x.c | 2 +-
> drivers/hwtracing/coresight/coresight-etm4x.h | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
> index 53e2fb6e86f6..40cf17df5023 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
> @@ -1021,7 +1021,7 @@ static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
>
> cpus_read_unlock();
>
> - if (etm4_arch_supported(drvdata->arch) == false) {
> + if (etm4_arch_supported(drvdata->arch >> 4) == false) {
I think it would be better to simply mask out the minor version number bits in
function etm4_arch_supported(). That way we can add more intelligence in there
in the future if we have to and we don't have to touch the calling code again.
Thanks,
Mathieu
> ret = -EINVAL;
> goto err_arch_supported;
> }
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
> index 52786e9d8926..05d4bd330881 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> @@ -136,7 +136,7 @@
> #define ETM_MAX_RES_SEL 16
> #define ETM_MAX_SS_CMP 8
>
> -#define ETM_ARCH_V4 0x40
> +#define ETM_ARCH_V4 0x4
> #define ETMv4_SYNC_MASK 0x1F
> #define ETM_CYC_THRESHOLD_MASK 0xFFF
> #define ETM_CYC_THRESHOLD_DEFAULT 0x100
> --
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
> of Code Aurora Forum, hosted by The Linux Foundation
>
