Re: [PATCHv5 4/7] coresight: etm4x: Add support to enable ETMv4.2

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 28/01/2019 19:14, 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 etm
> [    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@codeaurora.org>
> ---
>   drivers/hwtracing/coresight/coresight-etm4x.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
> index 53e2fb6e86f6..fe76b176974a 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
> @@ -55,7 +55,8 @@ static void etm4_os_unlock(struct etmv4_drvdata *drvdata)
>   
>   static bool etm4_arch_supported(u8 arch)
>   {
> -	switch (arch) {
> +	/* Mask out the minor version number */
> +	switch (arch & 0xf0) {
>   	case ETM_ARCH_V4:
>   		break;
>   	default:
> 

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>