[PATCH 0/2] Add tracepoints support for Qualcomm GENI Serial drivers

[PATCH 0/2] Add tracepoints support for Qualcomm GENI Serial drivers

[Praveen Talari]

Add tracepoints to the Qualcomm GENI (Generic Interface) serial driver.
These trace events enable runtime debugging and performance analysis of
UART operations.

The trace events cover UART termios configuration, clock setup, manual
control state, interrupt status, and actual transmitted/received data in
hexadecimal format.

Usage examples:

Enable all serial traces:
  echo 1 > /sys/kernel/debug/tracing/events/qcom_geni_serial/enable
  cat /sys/kernel/debug/tracing/trace_pipe

Example trace output:

2517.938432: geni_serial_clk_cfg: a94000.serial: desired_rate=1843200
     clk_rate=7372800 clk_div=4 clk_idx=0
2517.938753: geni_serial_irq: a94000.serial: m_irq=0x88800000
     s_irq=0x08000111 dma_tx=0x00000000 dma_rx=0x00000000
2517.938803: geni_serial_set_termios: a94000.serial: baud=115200 bpc=8
     tx_trans=0x00000002 tx_par=0x00000000 rx_trans=0x00000000
rx_par=0x00000000 stop=0
2517.938807: geni_serial_set_mctrl: a94000.serial: mctrl=0x8006
     uart_manual_rfr=0x00000000
2517.938818: geni_serial_get_mctrl: a94000.serial: mctrl=0x0160
     geni_ios=0x00000001
2517.939165: geni_serial_irq: a94000.serial: m_irq=0x00400000
     s_irq=0x00000000 dma_tx=0x00000000 dma_rx=0x00000000
2517.939592: geni_serial_tx_data: a94000.serial: tx_len=8 data=61 62 63
     64 65 66 67 68
2517.940610: geni_serial_irq: a94000.serial: m_irq=0x00000001
     s_irq=0x00000000 dma_tx=0x00000003 dma_rx=0x00000000
2517.942174: geni_serial_irq: a94000.serial: m_irq=0x08000000
     s_irq=0x08000100 dma_tx=0x00000000 dma_rx=0x00000003
2517.942323: geni_serial_rx_data: a94000.serial: rx_len=8 data=61 62 63
     64 65 66 67 68
2517.942680: geni_serial_set_mctrl: a94000.serial: mctrl=0x8000
     uart_manual_rfr=0x80000002

Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
---
Praveen Talari (2):
      serial: qcom-geni: trace: Add tracepoint support for Qualcomm GENI serial
      serial: qcom-geni: Add tracepoints for Qualcomm GENI serial driver

 drivers/tty/serial/qcom_geni_serial.c   |  27 ++++-
 include/trace/events/qcom_geni_serial.h | 173 ++++++++++++++++++++++++++++++++
 2 files changed, 196 insertions(+), 4 deletions(-)
---
base-commit: 1f5ffc672165ff851063a5fd044b727ab2517ae3
change-id: 20260427-add-tracepoints-for-qcom-geni-serial-948777218b7b

Best regards,
-- 
Praveen Talari <praveen.talari@oss.qualcomm.com>

[PATCH v1 1/2] serial: qcom-geni: trace: Add tracepoint support for Qualcomm GENI serial

[Praveen Talari]

Add tracepoint support to the Qualcomm GENI serial driver to provide
runtime visibility into driver behavior without requiring invasive debug
patches.

The trace events cover UART termios configuration, clock setup, modem
control state, interrupt status, and TX/RX data, making it easier to
diagnose communication issues in the field.

Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
---
 include/trace/events/qcom_geni_serial.h | 173 ++++++++++++++++++++++++++++++++
 1 file changed, 173 insertions(+)

diff --git a/include/trace/events/qcom_geni_serial.h b/include/trace/events/qcom_geni_serial.h
new file mode 100644
index 000000000000..f386d163907a
--- /dev/null
+++ b/include/trace/events/qcom_geni_serial.h
@@ -0,0 +1,173 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM qcom_geni_serial
+
+#if !defined(_TRACE_QCOM_GENI_SERIAL_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_QCOM_GENI_SERIAL_H
+
+#include <linux/device.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(geni_serial_set_termios,
+	    TP_PROTO(struct device *dev, unsigned int baud,
+		     unsigned int bits_per_char, u32 tx_trans_cfg,
+		     u32 tx_parity_cfg, u32 rx_trans_cfg,
+		     u32 rx_parity_cfg, u32 stop_bit_len),
+	    TP_ARGS(dev, baud, bits_per_char, tx_trans_cfg, tx_parity_cfg,
+		    rx_trans_cfg, rx_parity_cfg, stop_bit_len),
+
+	    TP_STRUCT__entry(__string(name, dev_name(dev))
+			     __field(unsigned int, baud)
+			     __field(unsigned int, bits_per_char)
+			     __field(u32, tx_trans_cfg)
+			     __field(u32, tx_parity_cfg)
+			     __field(u32, rx_trans_cfg)
+			     __field(u32, rx_parity_cfg)
+			     __field(u32, stop_bit_len)
+	    ),
+
+	    TP_fast_assign(__assign_str(name);
+			   __entry->baud = baud;
+			   __entry->bits_per_char = bits_per_char;
+			   __entry->tx_trans_cfg = tx_trans_cfg;
+			   __entry->tx_parity_cfg = tx_parity_cfg;
+			   __entry->rx_trans_cfg = rx_trans_cfg;
+			   __entry->rx_parity_cfg = rx_parity_cfg;
+			   __entry->stop_bit_len = stop_bit_len;
+	    ),
+
+	    TP_printk("%s: baud=%u bpc=%u tx_trans=0x%08x tx_par=0x%08x rx_trans=0x%08x rx_par=0x%08x stop=%u",
+		      __get_str(name), __entry->baud, __entry->bits_per_char,
+		      __entry->tx_trans_cfg, __entry->tx_parity_cfg,
+		      __entry->rx_trans_cfg, __entry->rx_parity_cfg,
+		      __entry->stop_bit_len)
+);
+
+TRACE_EVENT(geni_serial_clk_cfg,
+	    TP_PROTO(struct device *dev, unsigned int desired_rate,
+		     unsigned long clk_rate, unsigned int clk_div,
+		     unsigned int clk_idx),
+	    TP_ARGS(dev, desired_rate, clk_rate, clk_div, clk_idx),
+
+	    TP_STRUCT__entry(__string(name, dev_name(dev))
+			     __field(unsigned int, desired_rate)
+			     __field(unsigned long, clk_rate)
+			     __field(unsigned int, clk_div)
+			     __field(unsigned int, clk_idx)
+	    ),
+
+	    TP_fast_assign(__assign_str(name);
+			   __entry->desired_rate = desired_rate;
+			   __entry->clk_rate = clk_rate;
+			   __entry->clk_div = clk_div;
+			   __entry->clk_idx = clk_idx;
+	    ),
+
+	    TP_printk("%s: desired_rate=%u clk_rate=%lu clk_div=%u clk_idx=%u",
+		      __get_str(name), __entry->desired_rate, __entry->clk_rate,
+		      __entry->clk_div, __entry->clk_idx)
+);
+
+TRACE_EVENT(geni_serial_irq,
+	    TP_PROTO(struct device *dev, u32 m_irq, u32 s_irq,
+		     u32 dma_tx, u32 dma_rx),
+	    TP_ARGS(dev, m_irq, s_irq, dma_tx, dma_rx),
+
+	    TP_STRUCT__entry(__string(name, dev_name(dev))
+			     __field(u32, m_irq)
+			     __field(u32, s_irq)
+			     __field(u32, dma_tx)
+			     __field(u32, dma_rx)
+	    ),
+
+	    TP_fast_assign(__assign_str(name);
+			   __entry->m_irq = m_irq;
+			   __entry->s_irq = s_irq;
+			   __entry->dma_tx = dma_tx;
+			   __entry->dma_rx = dma_rx;
+	    ),
+
+	    TP_printk("%s: m_irq=0x%08x s_irq=0x%08x dma_tx=0x%08x dma_rx=0x%08x",
+		      __get_str(name), __entry->m_irq, __entry->s_irq,
+		      __entry->dma_tx, __entry->dma_rx)
+);
+
+TRACE_EVENT(geni_serial_tx_data,
+	    TP_PROTO(struct device *dev, const u8 *buf, unsigned int len),
+	    TP_ARGS(dev, buf, len),
+
+	    TP_STRUCT__entry(__string(name, dev_name(dev))
+			     __field(unsigned int, len)
+			     __dynamic_array(u8, data, len)
+	    ),
+
+	    TP_fast_assign(__assign_str(name);
+			   __entry->len = len;
+			   memcpy(__get_dynamic_array(data), buf, len);
+	    ),
+
+	    TP_printk("%s: tx_len=%u data=%s",
+		      __get_str(name), __entry->len,
+		      __print_hex(__get_dynamic_array(data), __entry->len))
+);
+
+TRACE_EVENT(geni_serial_rx_data,
+	    TP_PROTO(struct device *dev, const u8 *buf, unsigned int len),
+	    TP_ARGS(dev, buf, len),
+
+	    TP_STRUCT__entry(__string(name, dev_name(dev))
+			     __field(unsigned int, len)
+			     __dynamic_array(u8, data, len)
+	    ),
+
+	    TP_fast_assign(__assign_str(name);
+			   __entry->len = len;
+			   memcpy(__get_dynamic_array(data), buf, len);
+	    ),
+
+	    TP_printk("%s: rx_len=%u data=%s",
+		      __get_str(name), __entry->len,
+		      __print_hex(__get_dynamic_array(data), __entry->len))
+);
+
+TRACE_EVENT(geni_serial_set_mctrl,
+	    TP_PROTO(struct device *dev, unsigned int mctrl,
+		     u32 uart_manual_rfr),
+	    TP_ARGS(dev, mctrl, uart_manual_rfr),
+
+	    TP_STRUCT__entry(__string(name, dev_name(dev))
+			     __field(unsigned int, mctrl)
+			     __field(u32, uart_manual_rfr)
+	    ),
+
+	    TP_fast_assign(__assign_str(name);
+			   __entry->mctrl = mctrl;
+			   __entry->uart_manual_rfr = uart_manual_rfr;
+	    ),
+
+	    TP_printk("%s: mctrl=0x%04x uart_manual_rfr=0x%08x",
+		      __get_str(name), __entry->mctrl, __entry->uart_manual_rfr)
+);
+
+TRACE_EVENT(geni_serial_get_mctrl,
+	    TP_PROTO(struct device *dev, unsigned int mctrl, u32 geni_ios),
+	    TP_ARGS(dev, mctrl, geni_ios),
+
+	    TP_STRUCT__entry(__string(name, dev_name(dev))
+			     __field(unsigned int, mctrl)
+			     __field(u32, geni_ios)
+	    ),
+
+	    TP_fast_assign(__assign_str(name);
+			   __entry->mctrl = mctrl;
+			   __entry->geni_ios = geni_ios;
+	    ),
+
+	    TP_printk("%s: mctrl=0x%04x geni_ios=0x%08x",
+		      __get_str(name), __entry->mctrl, __entry->geni_ios)
+);
+
+#endif /* _TRACE_QCOM_GENI_SERIAL_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>

-- 
2.34.1

[PATCH v1 2/2] serial: qcom-geni: Add tracepoints for Qualcomm GENI serial driver

[Praveen Talari]

Add tracing to the Qualcomm GENI serial driver to improve runtime
observability.

Trace hooks are added at key points including termios and clock
configuration, manual control get/set, interrupt handling, and data
TX/RX paths.

Usage examples:

Enable all serial traces:
  echo 1 > /sys/kernel/debug/tracing/events/qcom_geni_serial/enable
  cat /sys/kernel/debug/tracing/trace_pipe

Example trace output:

2517.938432: geni_serial_clk_cfg: a94000.serial: desired_rate=1843200
     clk_rate=7372800 clk_div=4 clk_idx=0
2517.938753: geni_serial_irq: a94000.serial: m_irq=0x88800000
     s_irq=0x08000111 dma_tx=0x00000000 dma_rx=0x00000000
2517.938803: geni_serial_set_termios: a94000.serial: baud=115200 bpc=8
     tx_trans=0x00000002 tx_par=0x00000000 rx_trans=0x00000000
rx_par=0x00000000 stop=0
2517.938807: geni_serial_set_mctrl: a94000.serial: mctrl=0x8006
     uart_manual_rfr=0x00000000
2517.938818: geni_serial_get_mctrl: a94000.serial: mctrl=0x0160
     geni_ios=0x00000001
2517.939165: geni_serial_irq: a94000.serial: m_irq=0x00400000
     s_irq=0x00000000 dma_tx=0x00000000 dma_rx=0x00000000
2517.939592: geni_serial_tx_data: a94000.serial: tx_len=8 data=61 62 63
     64 65 66 67 68
2517.940610: geni_serial_irq: a94000.serial: m_irq=0x00000001
     s_irq=0x00000000 dma_tx=0x00000003 dma_rx=0x00000000
2517.942174: geni_serial_irq: a94000.serial: m_irq=0x08000000
     s_irq=0x08000100 dma_tx=0x00000000 dma_rx=0x00000003
2517.942323: geni_serial_rx_data: a94000.serial: rx_len=8 data=61 62 63
     64 65 66 67 68
2517.942680: geni_serial_set_mctrl: a94000.serial: mctrl=0x8000
     uart_manual_rfr=0x80000002

Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
---
 drivers/tty/serial/qcom_geni_serial.c | 27 +++++++++++++++++++++++----
 1 file changed, 23 insertions(+), 4 deletions(-)

diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c
index e6b0a55f0cfb..9e2de074d799 100644
--- a/drivers/tty/serial/qcom_geni_serial.c
+++ b/drivers/tty/serial/qcom_geni_serial.c
@@ -7,6 +7,9 @@
 /* Disable MMIO tracing to prevent excessive logging of unwanted MMIO traces */
 #define __DISABLE_TRACE_MMIO__
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/qcom_geni_serial.h>
+
 #include <linux/clk.h>
 #include <linux/console.h>
 #include <linux/io.h>
@@ -225,7 +228,7 @@ static void qcom_geni_serial_config_port(struct uart_port *uport, int cfg_flags)
 static unsigned int qcom_geni_serial_get_mctrl(struct uart_port *uport)
 {
 	unsigned int mctrl = TIOCM_DSR | TIOCM_CAR;
-	u32 geni_ios;
+	u32 geni_ios = 0;
 
 	if (uart_console(uport)) {
 		mctrl |= TIOCM_CTS;
@@ -235,6 +238,8 @@ static unsigned int qcom_geni_serial_get_mctrl(struct uart_port *uport)
 			mctrl |= TIOCM_CTS;
 	}
 
+	trace_geni_serial_get_mctrl(uport->dev, mctrl, geni_ios);
+
 	return mctrl;
 }
 
@@ -253,6 +258,8 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
 	if (!(mctrl & TIOCM_RTS) && !uport->suspended)
 		uart_manual_rfr = UART_MANUAL_RFR_EN | UART_RFR_NOT_READY;
 	writel(uart_manual_rfr, uport->membase + SE_UART_MANUAL_RFR);
+
+	trace_geni_serial_set_mctrl(uport->dev, mctrl, uart_manual_rfr);
 }
 
 static const char *qcom_geni_serial_get_type(struct uart_port *uport)
@@ -683,6 +690,8 @@ static void qcom_geni_serial_start_tx_dma(struct uart_port *uport)
 	xmit_size = kfifo_out_linear_ptr(&tport->xmit_fifo, &tail,
 			UART_XMIT_SIZE);
 
+	trace_geni_serial_tx_data(uport->dev, tail, xmit_size);
+
 	qcom_geni_set_rs485_mode(uport, SER_RS485_RTS_ON_SEND);
 
 	qcom_geni_serial_setup_tx(uport, xmit_size);
@@ -909,8 +918,10 @@ static void qcom_geni_serial_handle_rx_dma(struct uart_port *uport, bool drop)
 		return;
 	}
 
-	if (!drop)
+	if (!drop) {
+		trace_geni_serial_rx_data(uport->dev, port->rx_buf, rx_in);
 		handle_rx_uart(uport, rx_in);
+	}
 
 	ret = geni_se_rx_dma_prep(&port->se, port->rx_buf,
 				  DMA_RX_BUF_SIZE,
@@ -1069,6 +1080,10 @@ static irqreturn_t qcom_geni_serial_isr(int isr, void *dev)
 	geni_status = readl(uport->membase + SE_GENI_STATUS);
 	dma = readl(uport->membase + SE_GENI_DMA_MODE_EN);
 	m_irq_en = readl(uport->membase + SE_GENI_M_IRQ_EN);
+
+	trace_geni_serial_irq(uport->dev, m_irq_status, s_irq_status,
+			      dma_tx_status, dma_rx_status);
+
 	writel(m_irq_status, uport->membase + SE_GENI_M_IRQ_CLEAR);
 	writel(s_irq_status, uport->membase + SE_GENI_S_IRQ_CLEAR);
 	writel(dma_tx_status, uport->membase + SE_DMA_TX_IRQ_CLR);
@@ -1281,8 +1296,8 @@ static int geni_serial_set_rate(struct uart_port *uport, unsigned int baud)
 		return -EINVAL;
 	}
 
-	dev_dbg(port->se.dev, "desired_rate = %u, clk_rate = %lu, clk_div = %u\n, clk_idx = %u\n",
-		baud * sampling_rate, clk_rate, clk_div, clk_idx);
+	trace_geni_serial_clk_cfg(uport->dev, baud * sampling_rate, clk_rate,
+				  clk_div, clk_idx);
 
 	uport->uartclk = clk_rate;
 	port->clk_rate = clk_rate;
@@ -1432,6 +1447,10 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport,
 	writel(bits_per_char, uport->membase + SE_UART_TX_WORD_LEN);
 	writel(bits_per_char, uport->membase + SE_UART_RX_WORD_LEN);
 	writel(stop_bit_len, uport->membase + SE_UART_TX_STOP_BIT_LEN);
+
+	trace_geni_serial_set_termios(uport->dev, baud, bits_per_char,
+				      tx_trans_cfg, tx_parity_cfg, rx_trans_cfg,
+				      rx_parity_cfg, stop_bit_len);
 }
 
 #ifdef CONFIG_SERIAL_QCOM_GENI_CONSOLE

-- 
2.34.1

Re: [PATCH v1 1/2] serial: qcom-geni: trace: Add tracepoint support for Qualcomm GENI serial

[Steven Rostedt]

On Wed, 06 May 2026 22:54:44 +0530
Praveen Talari <praveen.talari@oss.qualcomm.com> wrote:

> +TRACE_EVENT(geni_serial_tx_data,
> +	    TP_PROTO(struct device *dev, const u8 *buf, unsigned int len),
> +	    TP_ARGS(dev, buf, len),
> +
> +	    TP_STRUCT__entry(__string(name, dev_name(dev))
> +			     __field(unsigned int, len)
> +			     __dynamic_array(u8, data, len)
> +	    ),
> +
> +	    TP_fast_assign(__assign_str(name);
> +			   __entry->len = len;
> +			   memcpy(__get_dynamic_array(data), buf, len);
> +	    ),
> +
> +	    TP_printk("%s: tx_len=%u data=%s",
> +		      __get_str(name), __entry->len,
> +		      __print_hex(__get_dynamic_array(data), __entry->len))
> +);
> +
> +TRACE_EVENT(geni_serial_rx_data,
> +	    TP_PROTO(struct device *dev, const u8 *buf, unsigned int len),
> +	    TP_ARGS(dev, buf, len),
> +
> +	    TP_STRUCT__entry(__string(name, dev_name(dev))
> +			     __field(unsigned int, len)
> +			     __dynamic_array(u8, data, len)
> +	    ),
> +
> +	    TP_fast_assign(__assign_str(name);
> +			   __entry->len = len;
> +			   memcpy(__get_dynamic_array(data), buf, len);
> +	    ),
> +
> +	    TP_printk("%s: rx_len=%u data=%s",

Do you really need to say "tx_len" and "rx_len", could it just be "len" and
have the name of the tracepoint show what it is?

Each TRACE_EVENT() is really just a:

  DECLARE_EVENT_CLASS() followed by a DEFINE_EVENT()

underneath.

And each TRACE_EVENT() costs around 5K in size, where most of that is in
the DECLARE_EVENT_CLASS() portion. Thus, you can save some memory by using
DECLARE_EVENT_CLASS() and then define the above two events with
DEFINE_EVENT().

-- Steve


> +		      __get_str(name), __entry->len,
> +		      __print_hex(__get_dynamic_array(data), __entry->len))
> +);
> +

Re: [PATCH v1 1/2] serial: qcom-geni: trace: Add tracepoint support for Qualcomm GENI serial

[Praveen Talari]

On 08-05-2026 22:55, Steven Rostedt wrote:
> On Wed, 06 May 2026 22:54:44 +0530
> Praveen Talari <praveen.talari@oss.qualcomm.com> wrote:
>
>> +TRACE_EVENT(geni_serial_tx_data,
>> +	    TP_PROTO(struct device *dev, const u8 *buf, unsigned int len),
>> +	    TP_ARGS(dev, buf, len),
>> +
>> +	    TP_STRUCT__entry(__string(name, dev_name(dev))
>> +			     __field(unsigned int, len)
>> +			     __dynamic_array(u8, data, len)
>> +	    ),
>> +
>> +	    TP_fast_assign(__assign_str(name);
>> +			   __entry->len = len;
>> +			   memcpy(__get_dynamic_array(data), buf, len);
>> +	    ),
>> +
>> +	    TP_printk("%s: tx_len=%u data=%s",
>> +		      __get_str(name), __entry->len,
>> +		      __print_hex(__get_dynamic_array(data), __entry->len))
>> +);
>> +
>> +TRACE_EVENT(geni_serial_rx_data,
>> +	    TP_PROTO(struct device *dev, const u8 *buf, unsigned int len),
>> +	    TP_ARGS(dev, buf, len),
>> +
>> +	    TP_STRUCT__entry(__string(name, dev_name(dev))
>> +			     __field(unsigned int, len)
>> +			     __dynamic_array(u8, data, len)
>> +	    ),
>> +
>> +	    TP_fast_assign(__assign_str(name);
>> +			   __entry->len = len;
>> +			   memcpy(__get_dynamic_array(data), buf, len);
>> +	    ),
>> +
>> +	    TP_printk("%s: rx_len=%u data=%s",
> Do you really need to say "tx_len" and "rx_len", could it just be "len" and
> have the name of the tracepoint show what it is?
Sure. I will review and update next patch.
>
> Each TRACE_EVENT() is really just a:
>
>    DECLARE_EVENT_CLASS() followed by a DEFINE_EVENT()
>
> underneath.
>
> And each TRACE_EVENT() costs around 5K in size, where most of that is in
> the DECLARE_EVENT_CLASS() portion. Thus, you can save some memory by using
> DECLARE_EVENT_CLASS() and then define the above two events with
> DEFINE_EVENT().

Thank you for suggestion and will update in next patch.

Thanks,

Praveen Talari

>
> -- Steve
>
>
>> +		      __get_str(name), __entry->len,
>> +		      __print_hex(__get_dynamic_array(data), __entry->len))
>> +);
>> +