[PATCH 6/8] coresight: cti: Remove hw_powered flag
Mike Leach
Mike.Leach at arm.com
Fri Feb 20 06:25:57 PST 2026
> -----Original Message-----
> From: Leo Yan <leo.yan at arm.com>
> Sent: Monday, February 9, 2026 6:01 PM
> To: Suzuki Poulose <Suzuki.Poulose at arm.com>; Mike Leach
> <Mike.Leach at arm.com>; James Clark <james.clark at linaro.org>; Alexander
> Shishkin <alexander.shishkin at linux.intel.com>; Greg Kroah-Hartman
> <gregkh at linuxfoundation.org>; Mathieu Poirier
> <mathieu.poirier at linaro.org>; Tingwei Zhang <quic_tingwei at quicinc.com>;
> Yingchao Deng <yingchao.deng at oss.qualcomm.com>; Jie Gan
> <jie.gan at oss.qualcomm.com>
> Cc: coresight at lists.linaro.org; linux-arm-kernel at lists.infradead.org; linux-
> kernel at vger.kernel.org; Leo Yan <Leo.Yan at arm.com>
> Subject: [PATCH 6/8] coresight: cti: Remove hw_powered flag
>
> Since the CPU PM code has been removed from the CTI driver and the device
> is enabled via runtime PM, pm_runtime_active() can be used to check
> whether the device is powered.
>
> As a result, the hw_powered flag is redundant, remove it.
>
> Signed-off-by: Leo Yan <leo.yan at arm.com>
> ---
> drivers/hwtracing/coresight/coresight-cti-core.c | 11 ++++-----
> drivers/hwtracing/coresight/coresight-cti-sysfs.c | 29 ++++++-----------------
> drivers/hwtracing/coresight/coresight-cti.h | 6 ++---
> 3 files changed, 13 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c
> b/drivers/hwtracing/coresight/coresight-cti-core.c
> index
> 48db87e2fd0f1a669f2d20a0014108da215e26fd..3b3b851a018851a8656e
> ba64e638c61f3d04b99f 100644
> --- a/drivers/hwtracing/coresight/coresight-cti-core.c
> +++ b/drivers/hwtracing/coresight/coresight-cti-core.c
> @@ -89,8 +89,8 @@ static int cti_enable_hw(struct cti_drvdata *drvdata)
>
> guard(raw_spinlock_irqsave)(&drvdata->spinlock);
>
> - /* no need to do anything if enabled or unpowered*/
> - if (config->hw_enabled || !config->hw_powered)
> + /* no need to do anything if enabled */
> + if (config->hw_enabled)
> goto cti_state_unchanged;
>
> /* claim the device */
> @@ -123,8 +123,8 @@ static int cti_disable_hw(struct cti_drvdata *drvdata)
> if (--drvdata->config.enable_req_count > 0)
> return 0;
>
> - /* no need to do anything if disabled or cpu unpowered */
> - if (!config->hw_enabled || !config->hw_powered)
> + /* no need to do anything if disabled */
> + if (!config->hw_enabled)
> return 0;
>
> CS_UNLOCK(drvdata->base);
> @@ -725,9 +725,6 @@ static int cti_probe(struct amba_device *adev, const
> struct amba_id *id)
> return PTR_ERR(pdata);
> }
>
> - /* default to powered - could change on PM notifications */
> - drvdata->config.hw_powered = true;
> -
> /* set up device name - will depend if cpu bound or otherwise */
> if (drvdata->ctidev.cpu >= 0)
> cti_desc.name = devm_kasprintf(dev, GFP_KERNEL,
> "cti_cpu%d",
> diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> index
> a22cc9a2bee24eb6115e7adb61880cc86d03e12e..9ab586a5c9a4fd2a64c54
> 2aaaaa625e2299edd62 100644
> --- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
> @@ -81,19 +81,12 @@ static ssize_t enable_show(struct device *dev,
> char *buf)
> {
> int enable_req;
> - bool enabled, powered;
> struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
>
> - scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock) {
> + scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock)
> enable_req = drvdata->config.enable_req_count;
> - powered = drvdata->config.hw_powered;
> - enabled = drvdata->config.hw_enabled;
> - }
>
> - if (powered)
> - return sprintf(buf, "%d\n", enabled);
> - else
> - return sprintf(buf, "%d\n", !!enable_req);
> + return sprintf(buf, "%d\n", !!enable_req);
> }
>
> static ssize_t enable_store(struct device *dev,
> @@ -131,11 +124,7 @@ static ssize_t powered_show(struct device *dev,
> struct device_attribute *attr,
> char *buf)
> {
> - bool powered;
> - struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
> -
> - scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock)
> - powered = drvdata->config.hw_powered;
> + bool powered = pm_runtime_active(dev->parent);
>
> return sprintf(buf, "%d\n", powered);
> }
> @@ -181,10 +170,8 @@ static ssize_t coresight_cti_reg_show(struct device
> *dev,
>
> pm_runtime_get_sync(dev->parent);
>
> - scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock) {
> - if (drvdata->config.hw_powered)
> - val = cti_read_single_reg(drvdata, cti_attr->off);
> - }
> + scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock)
> + val = cti_read_single_reg(drvdata, cti_attr->off);
>
> pm_runtime_put_sync(dev->parent);
> return sysfs_emit(buf, "0x%x\n", val);
> @@ -204,10 +191,8 @@ static __maybe_unused ssize_t
> coresight_cti_reg_store(struct device *dev,
>
> pm_runtime_get_sync(dev->parent);
>
> - scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock) {
> - if (drvdata->config.hw_powered)
> - cti_write_single_reg(drvdata, cti_attr->off, val);
> - }
> + scoped_guard(raw_spinlock_irqsave, &drvdata->spinlock)
> + cti_write_single_reg(drvdata, cti_attr->off, val);
>
> pm_runtime_put_sync(dev->parent);
> return size;
> diff --git a/drivers/hwtracing/coresight/coresight-cti.h
> b/drivers/hwtracing/coresight/coresight-cti.h
> index
> 400c1545b22bfe631144d24faceb354ff2d49166..c858847a5b80036fb4818
> 0ff7fbbfe684028cb89 100644
> --- a/drivers/hwtracing/coresight/coresight-cti.h
> +++ b/drivers/hwtracing/coresight/coresight-cti.h
> @@ -122,7 +122,6 @@ struct cti_device {
> * @asicctl_impl: true if asicctl is implemented.
> * @enable_req_count: CTI is enabled alongside >=1 associated devices.
> * @hw_enabled: true if hw is currently enabled.
> - * @hw_powered: true if associated cpu powered on, or no cpu.
> * @trig_in_use: bitfield of in triggers registered as in use.
> * @trig_out_use: bitfield of out triggers registered as in use.
> * @trig_out_filter: bitfield of out triggers that are blocked if filter
> @@ -146,7 +145,6 @@ struct cti_config {
> /* cti enable control */
> int enable_req_count;
> bool hw_enabled;
> - bool hw_powered;
>
> /* registered triggers and filtering */
> u32 trig_in_use;
> @@ -237,10 +235,10 @@ struct coresight_platform_data *
> coresight_cti_get_platform_data(struct device *dev);
> const char *cti_plat_get_node_name(struct fwnode_handle *fwnode);
>
> -/* cti powered and enabled */
> +/* Check if a cti device is enabled */
> static inline bool cti_is_active(struct cti_config *cfg)
> {
> - return cfg->hw_powered && cfg->hw_enabled;
> + return cfg->hw_enabled;
> }
>
> #endif /* _CORESIGHT_CORESIGHT_CTI_H */
>
> --
> 2.34.1
Reviewed-by: Mike Leach <mike.leach at arm.com>
More information about the linux-arm-kernel
mailing list