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coresight: etr: Don't allocate the new buffer when etr is enabled

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When ETR is enabled, new buffer is not necessary to be allocated even
if buffer size is changed. This change can avoid some unnecessary
allocation of ETR buffer.

Change-Id: Ia39a99bb46c5c3f18ffc19bcc2a5cdf9ca086bbb
Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
This commit is contained in:
Mao Jinlong 2022-09-06 08:23:43 +08:00 committed by Gerrit - the friendly Code Review server
parent cb5ed64bbf
commit 15c0fa5355
1 changed files with 16 additions and 16 deletions
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32
drivers/hwtracing/coresight/coresight-tmc-etr.c
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@ -1249,6 +1249,22 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
struct etr_buf *sysfs_buf = NULL, *new_buf = NULL, *free_buf = NULL;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->reading || drvdata->mode == CS_MODE_PERF) {
ret = -EBUSY;
goto unlock_out;
}
/*
* In sysFS mode we can have multiple writers per sink. Since this
* sink is already enabled no memory is needed and the HW need not be
* touched, even if the buffer size has changed.
*/
if (drvdata->mode == CS_MODE_SYSFS) {
atomic_inc(csdev->refcnt);
goto unlock_out;
}
/*
* If we are enabling the ETR from disabled state, we need to make
* sure we have a buffer with the right size. The etr_buf is not reset
@ -1257,7 +1273,6 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
* buffer, provided the size matches. Any allocation has to be done
* with the lock released.
*/
spin_lock_irqsave(&drvdata->spinlock, flags);
if ((drvdata->out_mode == TMC_ETR_OUT_MODE_MEM)
|| (drvdata->out_mode == TMC_ETR_OUT_MODE_USB &&
drvdata->usb_data->usb_mode ==
@ -1280,21 +1295,6 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
}
}
if (drvdata->reading || drvdata->mode == CS_MODE_PERF) {
ret = -EBUSY;
goto unlock_out;
}
/*
* In sysFS mode we can have multiple writers per sink. Since this
* sink is already enabled no memory is needed and the HW need not be
* touched, even if the buffer size has changed.
*/
if (drvdata->mode == CS_MODE_SYSFS) {
atomic_inc(csdev->refcnt);
goto unlock_out;
}
/*
* If we don't have a buffer or it doesn't match the requested size,
* use the buffer allocated above. Otherwise reuse the existing buffer.