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| author | Sanman Pradhan <psanman@juniper.net> | 2026-04-14 17:25:22 +0000 |
|---|---|---|
| committer | Suzuki K Poulose <suzuki.poulose@arm.com> | 2026-08-07 10:45:11 +0100 |
| commit | 856119909d8de99d540edbdfb5431efab936f649 (patch) | |
| tree | a444655abe895217dbabef99e9cdbadd73b025b6 | |
| parent | 75d42d990335322852ed5f7ce324b701c0949d79 (diff) | |
| download | linux-stable-856119909d8de99d540edbdfb5431efab936f649.tar.gz linux-stable-856119909d8de99d540edbdfb5431efab936f649.zip | |
hwtracing: hisi_ptt: Remove unnecessary trace buffer zeroing in trace_start()
hisi_ptt_trace_start() clears all four trace buffers before enabling
tracing.
This is unnecessary. On trace stop, hisi_ptt_update_aux() copies only
the number of bytes reported in HISI_PTT_TRACE_WR_STS. On buffer-full
interrupts, it copies a full completed buffer. In both cases the driver
only consumes data written by hardware.
Remove the buffer clearing from the trace start path.
Signed-off-by: Sanman Pradhan <psanman@juniper.net>
Reviewed-by: Yicong Yang <yangyccccc@gmail.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20260414172451.14331-3-sanman.pradhan@hpe.com
| -rw-r--r-- | drivers/hwtracing/ptt/hisi_ptt.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/drivers/hwtracing/ptt/hisi_ptt.c b/drivers/hwtracing/ptt/hisi_ptt.c index b5d851281fbf..a8f6986c8e1f 100644 --- a/drivers/hwtracing/ptt/hisi_ptt.c +++ b/drivers/hwtracing/ptt/hisi_ptt.c @@ -194,7 +194,6 @@ static int hisi_ptt_trace_start(struct hisi_ptt *hisi_ptt) { struct hisi_ptt_trace_ctrl *ctrl = &hisi_ptt->trace_ctrl; u32 val; - int i; /* Check device idle before start trace */ if (!hisi_ptt_wait_trace_hw_idle(hisi_ptt)) { @@ -222,10 +221,6 @@ static int hisi_ptt_trace_start(struct hisi_ptt *hisi_ptt) /* Reset the index of current buffer */ hisi_ptt->trace_ctrl.buf_index = 0; - /* Zero the trace buffers */ - for (i = 0; i < HISI_PTT_TRACE_BUF_CNT; i++) - memset(ctrl->trace_buf[i].addr, 0, HISI_PTT_TRACE_BUF_SIZE); - /* Clear the interrupt status */ writel(HISI_PTT_TRACE_INT_STAT_MASK, hisi_ptt->iobase + HISI_PTT_TRACE_INT_STAT); writel(0, hisi_ptt->iobase + HISI_PTT_TRACE_INT_MASK); |