Disable MMIO tracing for geni serial driver to prevent excessive logging. Any access over serial console would involve a lot of TX and RX register accesses (and few others), so these MMIO read/write trace events in these drivers cause a lot of unwanted noise because of the high frequency of such operations and it is not very useful tracing these events for such drivers. Given we want to enable these trace events on development devices (maybe not production devices) where performance also really matters so that we don't regress other components by wasting CPU cycles and memory collecting these traces, it makes more sense to disable these traces from such drivers. Also another reason to disable these traces would be to prevent recursive tracing when we display the trace buffer containing these MMIO trace events since writing onto serial console would further record MMIO traces. Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> Signed-off-by: Sai Prakash Ranjan <quic_saipraka@xxxxxxxxxxx> --- drivers/tty/serial/qcom_geni_serial.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 1543a6028856..75272585c3c3 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1,6 +1,9 @@ // SPDX-License-Identifier: GPL-2.0 // Copyright (c) 2017-2018, The Linux foundation. All rights reserved. +/* Disable MMIO tracing to prevent excessive logging of unwanted MMIO traces */ +#define __DISABLE_TRACE_MMIO__ + #include <linux/clk.h> #include <linux/console.h> #include <linux/io.h> -- 2.33.1
