uart_prepare_sysrq_char 1694 drivers/tty/serial/8250/8250_port.c if (uart_prepare_sysrq_char(port, ch)) uart_prepare_sysrq_char 504 drivers/tty/serial/qcom_geni_serial.c sysrq = uart_prepare_sysrq_char(uport, buf[c]);