[PATCH v5 0/2] Add tracepoints support for Qualcomm GENI Serial drivers

[PATCH v5 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>
---
Changes in v5:
- Remove serial trace header patch since it was accepted and merged.
- Added a new patch to fix for remove unwanted variable len.
- Link to v4: https://lore.kernel.org/all/20260526-add-tracepoints-for-qcom-geni-serial-v4-0-e94fbaec0232@oss.qualcomm.com

Changes in v4:
- Rebased patch(02/02) on latest linux-next.
- Link to v3: https://lore.kernel.org/all/20260518-add-tracepoints-for-qcom-geni-serial-v3-0-b4addb151376@oss.qualcomm.com

Changes in v3:
- Removed \n from geni_serial_tx_data and geni_serial_rx_data events.
- Resolved aligment issues in geni_serial_data, geni_serial_tx_data and
  geni_serial_rx_data events.
- Link to v2: https://lore.kernel.org/r/20260512-add-tracepoints-for-qcom-geni-serial-v2-0-a5726421b3af@oss.qualcomm.com

Changes in v2:
- removed multiple trace events for TX/RX events, instead used
  DECLARE_EVENT_CLASS and DEFINE_EVENT.
- Link to v1: https://lore.kernel.org/r/20260506-add-tracepoints-for-qcom-geni-serial-v1-0-544b22612e08@oss.qualcomm.com

To: Steven Rostedt <rostedt@goodmis.org>
To: Masami Hiramatsu <mhiramat@kernel.org>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Jiri Slaby <jirislaby@kernel.org>
To: konrad.dybcio@oss.qualcomm.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-kernel@vger.kernel.org
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-serial@vger.kernel.org
Cc: mukesh.savaliya@oss.qualcomm.com
Cc: aniket.randive@oss.qualcomm.com
Cc: chandana.chiluveru@oss.qualcomm.com

---
Praveen Talari (2):
      serial: qcom-geni: trace: Drop redundant len field from geni_serial_data
      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 |  7 +++----
 2 files changed, 26 insertions(+), 8 deletions(-)
---
base-commit: c425609d6ac4012c8bbf01ec2e10e801b1923a7b
change-id: 20260427-add-tracepoints-for-qcom-geni-serial-948777218b7b

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

[PATCH v5 1/2] serial: qcom-geni: trace: Drop redundant len field from geni_serial_data

[Praveen Talari]

The dynamic array stored in the ring buffer already carries its own
length in the array metadata. There is no need to also store it as a
separate scalar field in the entry struct.

Drop __field(unsigned int, len) and the corresponding __entry->len
assignment, and use __get_dynamic_array_len(data) in the TP_printk for
both the len=%u format argument and the __print_hex() size argument.
This saves 4 bytes per event on the ring buffer.

Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
---
 include/trace/events/qcom_geni_serial.h | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/include/trace/events/qcom_geni_serial.h b/include/trace/events/qcom_geni_serial.h
index 417ec01f9fc8..e1aa551d525e 100644
--- a/include/trace/events/qcom_geni_serial.h
+++ b/include/trace/events/qcom_geni_serial.h
@@ -97,18 +97,17 @@ DECLARE_EVENT_CLASS(geni_serial_data,
 		    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: len=%u data=%s",
-			      __get_str(name), __entry->len,
-			      __print_hex(__get_dynamic_array(data), __entry->len))
+			      __get_str(name), __get_dynamic_array_len(data),
+			      __print_hex(__get_dynamic_array(data),
+					  __get_dynamic_array_len(data)))
 );
 
 DEFINE_EVENT(geni_serial_data, geni_serial_tx_data,

-- 
2.34.1

[PATCH v5 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.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
---
v2->v3:
- Updated commit text(removed example as it was available on cover
  letter).
---
 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 d81b539cff7f..4b62e58d4918 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>
@@ -226,7 +229,7 @@ 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;
@@ -236,6 +239,8 @@ 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;
 }
 
@@ -254,6 +259,8 @@ static void qcom_geni_serial_set_mctrl(struct uart_port *uport,
 	if (port->manual_flow && !(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)
@@ -684,6 +691,8 @@ 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);
@@ -910,8 +919,10 @@ 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,
@@ -1082,6 +1093,10 @@ 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);
@@ -1294,8 +1309,8 @@ 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, 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;
@@ -1455,6 +1470,10 @@ 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 v5 1/2] serial: qcom-geni: trace: Drop redundant len field from geni_serial_data

[Konrad Dybcio]

On 6/15/26 4:16 PM, Praveen Talari wrote:
> The dynamic array stored in the ring buffer already carries its own
> length in the array metadata. There is no need to also store it as a
> separate scalar field in the entry struct.
> 
> Drop __field(unsigned int, len) and the corresponding __entry->len
> assignment, and use __get_dynamic_array_len(data) in the TP_printk for
> both the len=%u format argument and the __print_hex() size argument.
> This saves 4 bytes per event on the ring buffer.
> 
> Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
> ---

Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>

Konrad

Re: [PATCH v5 2/2] serial: qcom-geni: Add tracepoints for Qualcomm GENI serial driver

[Greg Kroah-Hartman]

On Mon, Jun 15, 2026 at 07:46:53PM +0530, Praveen Talari wrote:
> 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.
> 
> Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
> Signed-off-by: Praveen Talari <praveen.talari@oss.qualcomm.com>
> ---
> v2->v3:
> - Updated commit text(removed example as it was available on cover
>   letter).
> ---
>  drivers/tty/serial/qcom_geni_serial.c | 27 +++++++++++++++++++++++----
>  1 file changed, 23 insertions(+), 4 deletions(-)

Does not apply to my tty-next branch :(