Commit a699213d authored by Krzysztof Kozlowski's avatar Krzysztof Kozlowski Committed by Greg Kroah-Hartman
Browse files

serial: qcom-geni: Fix blocked task 



Revert commit 1afa7063 ("serial: qcom-geni: Enable PM runtime for
serial driver") and its dependent commit 86fa39dd ("serial:
qcom-geni: Enable Serial on SA8255p Qualcomm platforms") because the
first one causes regression - hang task on Qualcomm RB1 board (QRB2210)
and unable to use serial at all during normal boot:

  INFO: task kworker/u16:0:12 blocked for more than 42 seconds.
        Not tainted 6.17.0-rc1-00004-g53e760d89498 #9
  "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  task:kworker/u16:0   state:D stack:0     pid:12    tgid:12    ppid:2      task_flags:0x4208060 flags:0x00000010
  Workqueue: async async_run_entry_fn
  Call trace:
   __switch_to+0xe8/0x1a0 (T)
   __schedule+0x290/0x7c0
   schedule+0x34/0x118
   rpm_resume+0x14c/0x66c
   rpm_resume+0x2a4/0x66c
   rpm_resume+0x2a4/0x66c
   rpm_resume+0x2a4/0x66c
   __pm_runtime_resume+0x50/0x9c
   __driver_probe_device+0x58/0x120
   driver_probe_device+0x3c/0x154
   __driver_attach_async_helper+0x4c/0xc0
   async_run_entry_fn+0x34/0xe0
   process_one_work+0x148/0x290
   worker_thread+0x2c4/0x3e0
   kthread+0x118/0x1c0
   ret_from_fork+0x10/0x20

The issue was reported on 12th of August and was ignored by author of
commits introducing issue for two weeks.  Only after complaining author
produced a fix which did not work, so if original commits cannot be
reliably fixed for 5 weeks, they obviously are buggy and need to be
dropped.

Fixes: 1afa7063 ("serial: qcom-geni: Enable PM runtime for serial driver")
Reported-by: default avatarAlexey Klimov <alexey.klimov@linaro.org>
Closes: https://lore.kernel.org/all/DC0D53ZTNOBU.E8LSD5E5Z8TX@linaro.org/


Signed-off-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Tested-by: default avatarAlexey Klimov <alexey.klimov@linaro.org>
Reviewed-by: default avatarAlexey Klimov <alexey.klimov@linaro.org>
Reviewed-by: default avatarBryan O'Donoghue <bryan.odonoghue@linaro.org>
Link: https://lore.kernel.org/r/20250917010437.129912-2-krzysztof.kozlowski@linaro.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f83ec76b

drivers/tty/serial/qcom_geni_serial.c

+16 −160
Original line number Diff line number Diff line
@@ -11,7 +11,6 @@ 
#include <linux/irq.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/pm_domain.h>

#include <linux/pm_opp.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>
@@ -100,16 +99,10 @@ 
#define DMA_RX_BUF_SIZE		2048



static DEFINE_IDA(port_ida);

#define DOMAIN_IDX_POWER	0

#define DOMAIN_IDX_PERF		1



struct qcom_geni_device_data {

	bool console;

	enum geni_se_xfer_mode mode;

	struct dev_pm_domain_attach_data pd_data;

	int (*resources_init)(struct uart_port *uport);

	int (*set_rate)(struct uart_port *uport, unsigned int baud);

	int (*power_state)(struct uart_port *uport, bool state);

};



struct qcom_geni_private_data {
@@ -147,7 +140,6 @@ struct qcom_geni_serial_port { 


	struct qcom_geni_private_data private_data;

	const struct qcom_geni_device_data *dev_data;

	struct dev_pm_domain_list *pd_list;

};



static const struct uart_ops qcom_geni_console_pops;
@@ -1370,42 +1362,6 @@ static int geni_serial_set_rate(struct uart_port *uport, unsigned int baud) 
	return 0;

}



static int geni_serial_set_level(struct uart_port *uport, unsigned int baud)

{

	struct qcom_geni_serial_port *port = to_dev_port(uport);

	struct device *perf_dev = port->pd_list->pd_devs[DOMAIN_IDX_PERF];



	/*

	 * The performance protocol sets UART communication

	 * speeds by selecting different performance levels

	 * through the OPP framework.

	 *

	 * Supported perf levels for baudrates in firmware are below

	 * +---------------------+--------------------+

	 * |  Perf level value   |  Baudrate values   |

	 * +---------------------+--------------------+

	 * |      300            |      300           |

	 * |      1200           |      1200          |

	 * |      2400           |      2400          |

	 * |      4800           |      4800          |

	 * |      9600           |      9600          |

	 * |      19200          |      19200         |

	 * |      38400          |      38400         |

	 * |      57600          |      57600         |

	 * |      115200         |      115200        |

	 * |      230400         |      230400        |

	 * |      460800         |      460800        |

	 * |      921600         |      921600        |

	 * |      2000000        |      2000000       |

	 * |      3000000        |      3000000       |

	 * |      3200000        |      3200000       |

	 * |      4000000        |      4000000       |

	 * +---------------------+--------------------+

	 */



	return dev_pm_opp_set_level(perf_dev, baud);

}



static void qcom_geni_serial_set_termios(struct uart_port *uport,

					 struct ktermios *termios,

					 const struct ktermios *old)
@@ -1424,7 +1380,7 @@ static void qcom_geni_serial_set_termios(struct uart_port *uport, 
	/* baud rate */

	baud = uart_get_baud_rate(uport, termios, old, 300, 8000000);



	ret = port->dev_data->set_rate(uport, baud);

	ret = geni_serial_set_rate(uport, baud);

	if (ret)

		return;
@@ -1711,27 +1667,8 @@ static int geni_serial_resources_off(struct uart_port *uport) 
	return 0;

}



static int geni_serial_resource_state(struct uart_port *uport, bool power_on)

static int geni_serial_resource_init(struct qcom_geni_serial_port *port)

{

	return power_on ? geni_serial_resources_on(uport) : geni_serial_resources_off(uport);

}



static int geni_serial_pwr_init(struct uart_port *uport)

{

	struct qcom_geni_serial_port *port = to_dev_port(uport);

	int ret;



	ret = dev_pm_domain_attach_list(port->se.dev,

					&port->dev_data->pd_data, &port->pd_list);

	if (ret <= 0)

		return -EINVAL;



	return 0;

}



static int geni_serial_resource_init(struct uart_port *uport)

{

	struct qcom_geni_serial_port *port = to_dev_port(uport);

	int ret;



	port->se.clk = devm_clk_get(port->se.dev, "se");
@@ -1776,10 +1713,10 @@ static void qcom_geni_serial_pm(struct uart_port *uport, 
		old_state = UART_PM_STATE_OFF;



	if (new_state == UART_PM_STATE_ON && old_state == UART_PM_STATE_OFF)

		pm_runtime_resume_and_get(uport->dev);

		geni_serial_resources_on(uport);

	else if (new_state == UART_PM_STATE_OFF &&

		 old_state == UART_PM_STATE_ON)

		pm_runtime_put_sync(uport->dev);

		geni_serial_resources_off(uport);



}
@@ -1882,16 +1819,13 @@ static int qcom_geni_serial_probe(struct platform_device *pdev) 
	port->se.dev = &pdev->dev;

	port->se.wrapper = dev_get_drvdata(pdev->dev.parent);



	ret = port->dev_data->resources_init(uport);

	ret = geni_serial_resource_init(port);

	if (ret)

		return ret;



	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!res) {

		ret = -EINVAL;

		goto error;

	}



	if (!res)

		return -EINVAL;

	uport->mapbase = res->start;



	uport->rs485_config = qcom_geni_rs485_config;
@@ -1903,26 +1837,19 @@ static int qcom_geni_serial_probe(struct platform_device *pdev) 
	if (!data->console) {

		port->rx_buf = devm_kzalloc(uport->dev,

					    DMA_RX_BUF_SIZE, GFP_KERNEL);

		if (!port->rx_buf) {

			ret = -ENOMEM;

			goto error;

		}

		if (!port->rx_buf)

			return -ENOMEM;

	}



	port->name = devm_kasprintf(uport->dev, GFP_KERNEL,

			"qcom_geni_serial_%s%d",

			uart_console(uport) ? "console" : "uart", uport->line);

	if (!port->name) {

		ret = -ENOMEM;

		goto error;

	}

	if (!port->name)

		return -ENOMEM;



	irq = platform_get_irq(pdev, 0);

	if (irq < 0) {

		ret = irq;

		goto error;

	}



	if (irq < 0)

		return irq;

	uport->irq = irq;

	uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_QCOM_GENI_CONSOLE);
@@ -1944,18 +1871,16 @@ static int qcom_geni_serial_probe(struct platform_device *pdev) 
			IRQF_TRIGGER_HIGH, port->name, uport);

	if (ret) {

		dev_err(uport->dev, "Failed to get IRQ ret %d\n", ret);

		goto error;

		return ret;

	}



	ret = uart_get_rs485_mode(uport);

	if (ret)

		return ret;



	devm_pm_runtime_enable(port->se.dev);



	ret = uart_add_one_port(drv, uport);

	if (ret)

		goto error;

		return ret;



	if (port->wakeup_irq > 0) {

		device_init_wakeup(&pdev->dev, true);
@@ -1965,15 +1890,11 @@ static int qcom_geni_serial_probe(struct platform_device *pdev) 
			device_init_wakeup(&pdev->dev, false);

			ida_free(&port_ida, uport->line);

			uart_remove_one_port(drv, uport);

			goto error;

			return ret;

		}

	}



	return 0;



error:

	dev_pm_domain_detach_list(port->pd_list);

	return ret;

}



static void qcom_geni_serial_remove(struct platform_device *pdev)
@@ -1986,31 +1907,6 @@ static void qcom_geni_serial_remove(struct platform_device *pdev) 
	device_init_wakeup(&pdev->dev, false);

	ida_free(&port_ida, uport->line);

	uart_remove_one_port(drv, &port->uport);

	dev_pm_domain_detach_list(port->pd_list);

}



static int __maybe_unused qcom_geni_serial_runtime_suspend(struct device *dev)

{

	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);

	struct uart_port *uport = &port->uport;

	int ret = 0;



	if (port->dev_data->power_state)

		ret = port->dev_data->power_state(uport, false);



	return ret;

}



static int __maybe_unused qcom_geni_serial_runtime_resume(struct device *dev)

{

	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);

	struct uart_port *uport = &port->uport;

	int ret = 0;



	if (port->dev_data->power_state)

		ret = port->dev_data->power_state(uport, true);



	return ret;

}



static int qcom_geni_serial_suspend(struct device *dev)
@@ -2048,46 +1944,14 @@ static int qcom_geni_serial_resume(struct device *dev) 
static const struct qcom_geni_device_data qcom_geni_console_data = {

	.console = true,

	.mode = GENI_SE_FIFO,

	.resources_init = geni_serial_resource_init,

	.set_rate = geni_serial_set_rate,

	.power_state = geni_serial_resource_state,

};



static const struct qcom_geni_device_data qcom_geni_uart_data = {

	.console = false,

	.mode = GENI_SE_DMA,

	.resources_init = geni_serial_resource_init,

	.set_rate = geni_serial_set_rate,

	.power_state = geni_serial_resource_state,

};



static const struct qcom_geni_device_data sa8255p_qcom_geni_console_data = {

	.console = true,

	.mode = GENI_SE_FIFO,

	.pd_data = {

		.pd_flags = PD_FLAG_DEV_LINK_ON,

		.pd_names = (const char*[]) { "power", "perf" },

		.num_pd_names = 2,

	},

	.resources_init = geni_serial_pwr_init,

	.set_rate = geni_serial_set_level,

};



static const struct qcom_geni_device_data sa8255p_qcom_geni_uart_data = {

	.console = false,

	.mode = GENI_SE_DMA,

	.pd_data = {

		.pd_flags = PD_FLAG_DEV_LINK_ON,

		.pd_names = (const char*[]) { "power", "perf" },

		.num_pd_names = 2,

	},

	.resources_init = geni_serial_pwr_init,

	.set_rate = geni_serial_set_level,

};



static const struct dev_pm_ops qcom_geni_serial_pm_ops = {

	SET_RUNTIME_PM_OPS(qcom_geni_serial_runtime_suspend,

			   qcom_geni_serial_runtime_resume, NULL)

	SYSTEM_SLEEP_PM_OPS(qcom_geni_serial_suspend, qcom_geni_serial_resume)

};
@@ -2096,18 +1960,10 @@ static const struct of_device_id qcom_geni_serial_match_table[] = { 
		.compatible = "qcom,geni-debug-uart",

		.data = &qcom_geni_console_data,

	},

	{

		.compatible = "qcom,sa8255p-geni-debug-uart",

		.data = &sa8255p_qcom_geni_console_data,

	},

	{

		.compatible = "qcom,geni-uart",

		.data = &qcom_geni_uart_data,

	},

	{

		.compatible = "qcom,sa8255p-geni-uart",

		.data = &sa8255p_qcom_geni_uart_data,

	},

	{}

};

MODULE_DEVICE_TABLE(of, qcom_geni_serial_match_table);