Commit 38eb1577 authored by Johan Hovold's avatar Johan Hovold Committed by Wen Zhiwei
Browse files

serial: qcom-geni: revert broken hibernation support 

stable inclusion
from stable-v6.6.58
commit 7176aee5a1b20ae4da1082d6fc59a3b58383f079
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IB3BSC

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=7176aee5a1b20ae4da1082d6fc59a3b58383f079



--------------------------------

commit 19df76662a33d2f2fc41a66607cb8285fc02d6ec upstream.

This reverts commit 35781d83.

Hibernation is not supported on Qualcomm platforms with mainline
kernels yet a broken vendor implementation for the GENI serial driver
made it upstream.

This is effectively dead code that cannot be tested and should just be
removed, but if these paths were ever hit for an open non-console port
they would crash the machine as the driver would fail to enable clocks
during restore() (i.e. all ports would have to be closed by drivers and
user space before hibernating the system to avoid this as a comment in
the code hinted at).

The broken implementation also added a random call to enable the
receiver in the port setup code where it does not belong and which
enables the receiver prematurely for console ports.

Fixes: 35781d83 ("tty: serial: qcom-geni-serial: Add support for Hibernation feature")
Cc: stable@vger.kernel.org	# 6.2
Cc: Aniket Randive <quic_arandive@quicinc.com>
Signed-off-by: default avatarJohan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20241009145110.16847-3-johan+linaro@kernel.org


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarWen Zhiwei <wenzhiwei@kylinos.cn>
parent bbd3cab9

drivers/tty/serial/qcom_geni_serial.c

+2 −39
Original line number Diff line number Diff line
@@ -1134,7 +1134,6 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport) 
			       false, true, true);

	geni_se_init(&port->se, UART_RX_WM, port->rx_fifo_depth - 2);

	geni_se_select_mode(&port->se, port->dev_data->mode);

	qcom_geni_serial_start_rx(uport);

	port->setup = true;



	return 0;
@@ -1764,38 +1763,6 @@ static int qcom_geni_serial_sys_resume(struct device *dev) 
	return ret;

}



static int qcom_geni_serial_sys_hib_resume(struct device *dev)

{

	int ret = 0;

	struct uart_port *uport;

	struct qcom_geni_private_data *private_data;

	struct qcom_geni_serial_port *port = dev_get_drvdata(dev);



	uport = &port->uport;

	private_data = uport->private_data;



	if (uart_console(uport)) {

		geni_icc_set_tag(&port->se, QCOM_ICC_TAG_ALWAYS);

		geni_icc_set_bw(&port->se);

		ret = uart_resume_port(private_data->drv, uport);

		/*

		 * For hibernation usecase clients for

		 * console UART won't call port setup during restore,

		 * hence call port setup for console uart.

		 */

		qcom_geni_serial_port_setup(uport);

	} else {

		/*

		 * Peripheral register settings are lost during hibernation.

		 * Update setup flag such that port setup happens again

		 * during next session. Clients of HS-UART will close and

		 * open the port during hibernation.

		 */

		port->setup = false;

	}

	return ret;

}



static const struct qcom_geni_device_data qcom_geni_console_data = {

	.console = true,

	.mode = GENI_SE_FIFO,
@@ -1807,12 +1774,8 @@ static const struct qcom_geni_device_data qcom_geni_uart_data = { 
};



static const struct dev_pm_ops qcom_geni_serial_pm_ops = {

	.suspend = pm_sleep_ptr(qcom_geni_serial_sys_suspend),

	.resume = pm_sleep_ptr(qcom_geni_serial_sys_resume),

	.freeze = pm_sleep_ptr(qcom_geni_serial_sys_suspend),

	.poweroff = pm_sleep_ptr(qcom_geni_serial_sys_suspend),

	.restore = pm_sleep_ptr(qcom_geni_serial_sys_hib_resume),

	.thaw = pm_sleep_ptr(qcom_geni_serial_sys_hib_resume),

	SYSTEM_SLEEP_PM_OPS(qcom_geni_serial_sys_suspend,

					qcom_geni_serial_sys_resume)

};



static const struct of_device_id qcom_geni_serial_match_table[] = {