From: Suzuki K Poulose <suzuki.poulose@arm•com>
To: Yeoreum Yun <yeoreum.yun@arm•com>,
coresight@lists•linaro.org, linux-arm-kernel@lists•infradead.org,
linux-kernel@vger•kernel.org
Cc: mike.leach@arm•com, james.clark@linaro•org,
alexander.shishkin@linux•intel.com, leo.yan@arm•com,
jie.gan@oss•qualcomm.com
Subject: Re: [PATCH v7 02/13] coresight: etm4x: fix underflow for nrseqstate
Date: Mon, 1 Jun 2026 10:52:45 +0100 [thread overview]
Message-ID: <24427ef2-8d32-4c29-b652-bf1019e04f40@arm.com> (raw)
In-Reply-To: <20260519154812.254884-3-yeoreum.yun@arm.com>
On 19/05/2026 16:48, Yeoreum Yun wrote:
> TCRSEQEVR<n> is implemented only when TCRIDR5.NUMSEQSTATE is 0b100,
> in which case n ranges from 0 to 2; otherwise, TCRIDR5.NUMSEQSTATE is 0b000.
>
> Therefore, drvdata->nrseqstate should be checked before entering the loop.
s/TCR/TRC/g ^^^ and every other patch in the series. Seem like you have
been playing with the MMU code ;-)
>
> Link: https://developer.arm.com/documentation/ihi0064/latest/ [0]
> Fixes: 2e1cdfe184b5 ("coresight-etm4x: Adding CoreSight ETM4x driver")
> Reviewed-by: Leo Yan <leo.yan@arm•com>
> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm•com>
> ---
> .../hwtracing/coresight/coresight-etm4x-core.c | 18 ++++++++++--------
> .../coresight/coresight-etm4x-sysfs.c | 2 ++
> 2 files changed, 12 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index 1e3b0344dc00..94b9385e964a 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -542,9 +542,11 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
> etm4x_relaxed_write32(csa, config->vissctlr, TRCVISSCTLR);
> if (drvdata->nr_pe_cmp)
> etm4x_relaxed_write32(csa, config->vipcssctlr, TRCVIPCSSCTLR);
> - for (i = 0; i < drvdata->nrseqstate - 1; i++)
> - etm4x_relaxed_write32(csa, config->seq_ctrl[i], TRCSEQEVRn(i));
> +
> if (drvdata->nrseqstate) {
> + for (i = 0; i < drvdata->nrseqstate - 1; i++)
> + etm4x_relaxed_write32(csa, config->seq_ctrl[i], TRCSEQEVRn(i));
Looking at this again, I think we are contemplating two different values
from a single variable (blame the architecture). Instead, we should:
1. Disconnect number of TRCSEQEVRn from drvdata->nrseqstate, and add
nr_seq_ctrls to drvdata and initialise this at probe.
for (i = 0; i < drvdata->nr_seq_ctrls; i++)
Suzuki
> +
> etm4x_relaxed_write32(csa, config->seq_rst, TRCSEQRSTEVR);
> etm4x_relaxed_write32(csa, config->seq_state, TRCSEQSTR);
> }
> @@ -1896,10 +1898,10 @@ static int etm4_cpu_save(struct coresight_device *csdev)
> if (drvdata->nr_pe_cmp)
> state->trcvipcssctlr = etm4x_read32(csa, TRCVIPCSSCTLR);
>
> - for (i = 0; i < drvdata->nrseqstate - 1; i++)
> - state->trcseqevr[i] = etm4x_read32(csa, TRCSEQEVRn(i));
> -
> if (drvdata->nrseqstate) {
> + for (i = 0; i < drvdata->nrseqstate - 1; i++)
> + state->trcseqevr[i] = etm4x_read32(csa, TRCSEQEVRn(i));
> +
> state->trcseqrstevr = etm4x_read32(csa, TRCSEQRSTEVR);
> state->trcseqstr = etm4x_read32(csa, TRCSEQSTR);
> }
> @@ -2009,10 +2011,10 @@ static void etm4_cpu_restore(struct coresight_device *csdev)
> if (drvdata->nr_pe_cmp)
> etm4x_relaxed_write32(csa, state->trcvipcssctlr, TRCVIPCSSCTLR);
>
> - for (i = 0; i < drvdata->nrseqstate - 1; i++)
> - etm4x_relaxed_write32(csa, state->trcseqevr[i], TRCSEQEVRn(i));
> -
> if (drvdata->nrseqstate) {
> + for (i = 0; i < drvdata->nrseqstate - 1; i++)
> + etm4x_relaxed_write32(csa, state->trcseqevr[i], TRCSEQEVRn(i));
> +
> etm4x_relaxed_write32(csa, state->trcseqrstevr, TRCSEQRSTEVR);
> etm4x_relaxed_write32(csa, state->trcseqstr, TRCSEQSTR);
> }
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> index e9eeea6240d5..0e1ad175aa1e 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> @@ -1395,6 +1395,8 @@ static ssize_t seq_idx_store(struct device *dev,
> struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
> struct etmv4_config *config = &drvdata->config;
>
> + if (!drvdata->nrseqstate)
> + return -ENOTSUPP;
> if (kstrtoul(buf, 16, &val))
> return -EINVAL;
> if (val >= drvdata->nrseqstate - 1)
next prev parent reply other threads:[~2026-06-01 9:52 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-19 15:47 [PATCH v7 00/13] fix several inconsistencies with sysfs configuration in etmX Yeoreum Yun
2026-05-19 15:48 ` [PATCH v7 01/13] coresight: etm4x: fix wrong check of etm4x_sspcicrn_present() Yeoreum Yun
2026-05-19 15:48 ` [PATCH v7 02/13] coresight: etm4x: fix underflow for nrseqstate Yeoreum Yun
2026-06-01 9:40 ` Suzuki K Poulose
2026-06-01 10:08 ` Yeoreum Yun
2026-06-01 10:13 ` Suzuki K Poulose
2026-06-01 10:15 ` Yeoreum Yun
2026-06-01 9:52 ` Suzuki K Poulose [this message]
2026-06-01 10:12 ` Yeoreum Yun
2026-05-19 15:48 ` [PATCH v7 03/13] coresight: etm4x: introduce ETM_MAX_SEQ_TRANSITIONS Yeoreum Yun
2026-05-28 12:58 ` Leo Yan
2026-05-28 13:47 ` Yeoreum Yun
2026-06-01 9:53 ` Suzuki K Poulose
2026-06-01 11:14 ` Yeoreum Yun
2026-05-19 15:48 ` [PATCH v7 04/13] coresight: etm4x: introduce struct etm4_caps Yeoreum Yun
2026-05-19 15:48 ` [PATCH v7 05/13] coresight: etm4x: exclude ss_status from drvdata->config Yeoreum Yun
2026-05-28 13:30 ` Leo Yan
2026-05-28 13:46 ` Yeoreum Yun
2026-06-01 11:27 ` Suzuki K Poulose
2026-06-01 11:52 ` Yeoreum Yun
2026-06-04 9:15 ` Suzuki K Poulose
2026-05-19 15:48 ` [PATCH v7 06/13] coresight: etm4x: remove redundant fields in etmv4_save_state Yeoreum Yun
2026-05-19 15:48 ` [PATCH v7 07/13] coresight: etm4x: fix leaked trace id Yeoreum Yun
2026-05-19 15:48 ` [PATCH v7 08/13] coresight: etm4x: fix inconsistencies with sysfs configuration Yeoreum Yun
2026-05-28 14:09 ` Leo Yan
2026-05-28 14:26 ` Yeoreum Yun
2026-05-28 14:56 ` Leo Yan
2026-05-28 15:22 ` Yeoreum Yun
2026-06-01 15:38 ` Suzuki K Poulose
2026-05-19 15:48 ` [PATCH v7 09/13] coresight: etm4x: missing cscfg_csdev_disable_active_config() in perf enable Yeoreum Yun
2026-05-28 14:33 ` Leo Yan
2026-05-28 14:43 ` Yeoreum Yun
2026-05-28 15:26 ` Leo Yan
2026-05-28 16:01 ` Yeoreum Yun
2026-06-01 16:11 ` Suzuki K Poulose
2026-06-01 16:41 ` Yeoreum Yun
2026-05-19 15:48 ` [PATCH v7 10/13] coresight: etm3x: change drvdata->spinlock type to raw_spin_lock_t Yeoreum Yun
2026-05-19 15:48 ` [PATCH v7 11/13] coresight: etm3x: introduce struct etm_caps Yeoreum Yun
2026-05-19 15:48 ` [PATCH v7 12/13] coresight: etm3x: fix inconsistencies with sysfs configuration Yeoreum Yun
2026-05-19 15:48 ` [PATCH v7 13/13] coresight: etm3x: remove redundant cpu online check on etm_enable_sysfs() Yeoreum Yun
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