Re: [PATCH v7 03/13] coresight: etm4x: introduce ETM_MAX_SEQ_TRANSITIONS

[Yeoreum Yun <yeoreum.yun@arm.com>]

On Mon, Jun 01, 2026 at 10:53:38AM +0100, Suzuki K Poulose wrote:
> On 19/05/2026 16:48, Yeoreum Yun wrote:
> > According to IHI006H Embedded Trace Macrocell Architecture
> > Specification [0], n could be 0-2 for TCRSEQEVR<n> when
> > TCRIDR5.NUMSEQSTATE is 0b100.
> > 
> > Therefore, introduce ETM_MAX_SEQ_TRANSITIONS macro and apply this
> > in TCRSEQEVR<n> relevant fields.
> > 
> > Link: https://developer.arm.com/documentation/ihi0064/latest/ [0]
> > Suggestedby: Leo Yan <leo.yan@arm.com>
> > Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> > ---
> >   drivers/hwtracing/coresight/coresight-etm4x-cfg.c | 2 +-
> >   drivers/hwtracing/coresight/coresight-etm4x.h     | 5 +++--
> >   2 files changed, 4 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> > index c302072b293a..e1a59b434505 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> > @@ -76,7 +76,7 @@ static int etm4_cfg_map_reg_offset(struct etmv4_drvdata *drvdata,
> >   	} else if ((offset & GENMASK(11, 4)) == TRCSEQEVRn(0)) {
> >   		/* sequencer state control registers */
> >   		idx = (offset & GENMASK(3, 0)) / 4;
> > -		if (idx < ETM_MAX_SEQ_STATES) {
> > +		if (idx < ETM_MAX_SEQ_TRANSITIONS) {
> >   			reg_csdev->driver_regval = &drvcfg->seq_ctrl[idx];
> >   			err = 0;
> >   		}
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
> > index 89d81ce4e04e..60e08ab085c5 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> > @@ -614,6 +614,7 @@ static inline u32 etm4_res_sel_pair(u8 res_sel_idx)
> >   #define ETM_MAX_NR_PE			8
> >   #define ETMv4_MAX_CNTR			4
> >   #define ETM_MAX_SEQ_STATES		4
> > +#define ETM_MAX_SEQ_TRANSITIONS		(ETM_MAX_SEQ_STATES - 1)
> 
> Similar to the other comment on the patch, please don't tie this to
> SEQ_STATES. Simpl define.
> 
> #define ETM_MAX_SEQ_CTRLS		3

Okay. I'll untie them. Thanks!

[...]

-- 
Sincerely,
Yeoreum Yun