Re: [PATCH v6 04/13] coresight: etm4x: exclude ss_status from drvdata->config

[Leo Yan <leo.yan@arm.com>]

On Wed, Apr 22, 2026 at 02:21:54PM +0100, Yeoreum Yun wrote:

[...]

> @@ -573,11 +573,9 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
>  		etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i));
>  
>  	for (i = 0; i < caps->nr_ss_cmp; i++) {
> -		/* always clear status bit on restart if using single-shot */
> -		if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
> -			config->ss_status[i] &= ~TRCSSCSRn_STATUS;
>  		etm4x_relaxed_write32(csa, config->ss_ctrl[i], TRCSSCCRn(i));
> -		etm4x_relaxed_write32(csa, config->ss_status[i], TRCSSCSRn(i));
> +		/* always clear status and pending bits on restart if using single-shot */
> +		etm4x_relaxed_write32(csa, 0x0, TRCSSCSRn(i));

After confirmed with hardware team, we should preserve status bits
(including STATUS and PENDING bits) during a session. So here we should
set drvdata->ss_status to TRCSSCSRn.

> @@ -1503,8 +1501,9 @@ static void etm4_init_arch_data(void *info)
>  	 */
>  	caps->nr_ss_cmp = FIELD_GET(TRCIDR4_NUMSSCC_MASK, etmidr4);
>  	for (i = 0; i < caps->nr_ss_cmp; i++) {
> -		drvdata->config.ss_status[i] =
> -			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
> +		drvdata->ss_status[i] = etm4x_relaxed_read32(csa, TRCSSCSRn(i));
> +		drvdata->ss_status[i] &= (TRCSSCSRn_PC | TRCSSCSRn_DV |
> +					  TRCSSCSRn_DA | TRCSSCSRn_INST);

It is fine for read these capacity bits when probe, but we need to clear
status when a session is starting to avoid the stale value left from
previous session:

  drvdata->ss_status[idx] &= ~(TRCSSCSRn_STATUS | TRCSSCSRn_PENDING);

We can do this in etm4_parse_event_config() for perf mode, and might
create a new function (say etm4_parse_sysfs_config()) for preparing
config for sysfs mode?

The rest looks good to me.

Thanks,
Leo