Issue

Description of problem: Customer has a machine with the Synopsys DesignWare APB UART. The serial ports are MMIO based: [ 4.587543] dw-apb-uart.6: ttyS0 at MMIO 0x4017006000 (irq = 33, base_baud = 6250000) is a 16550A [ 4.599879] dw-apb-uart.7: ttyS1 at MMIO 0x4017007000 (irq = 16, base_baud = 6250000) is a 16550A Kernel is configured to use ttyS0 as console: BOOT_IMAGE=(hd1,gpt2)/vmlinuz-5.14.0-162.6.1.el9_1.x86_64 root=/dev/mapper/rhel-root ro rhgb quiet crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap console=ttyS0,115200n8 So on system boot, a serial-getty@ttyS0 should be be started automatically by systemd-getty-generator but it fails to do it. Version-Release number of selected component (if applicable): RHEL 9.1 How reproducible: Always Steps to Reproduce: 1. Install RHEL 9.1 on a machine whose serial ports are MMIO-based. 2. Reboot the system 3. Check if a serial-getty@ttyS0 is started Actual results: serial-getty@ttyS0 is not started Expected results: serial-getty@ttyS0 should be started Additional info: From the system sosreport: $ fgrep w -e ttyS0 -e getty sos_commands/logs/journalctl_no-pager_catalog_-boot Mar 08 09:17:25 localhost kernel: Command line: BOOT_IMAGE=(hd1,gpt2)/vmlinuz-5.14.0-162.6.1.el9_1.x86_64 root=/dev/mapper/rhel-root ro rhgb quiet crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap console=ttyS0,115200n8 Mar 08 09:17:25 localhost kernel: Kernel command line: BOOT_IMAGE=(hd1,gpt2)/vmlinuz-5.14.0-162.6.1.el9_1.x86_64 root=/dev/mapper/rhel-root ro rhgb quiet crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap console=ttyS0,115200n8 Mar 08 09:17:25 localhost kernel: printk: console [ttyS0] enabled Mar 08 09:17:25 localhost dracut-cmdline[353]: Using kernel command line parameters: BOOT_IMAGE=(hd1,gpt2)/vmlinuz-5.14.0-162.6.1.el9_1.x86_64 root=/dev/mapper/rhel-root ro rhgb quiet crashkernel=1G-4G:192M,4G-64G:256M,64G-:512M resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap console=ttyS0,115200n8 Mar 08 09:17:27 localhost systemd[1]: Created slice Slice /system/getty. Mar 08 09:17:28 localhost kernel: printk: console [ttyS0] disabled Mar 08 09:17:28 localhost kernel: dw-apb-uart.6: ttyS0 at MMIO 0x4017006000 (irq = 33, base_baud = 6250000) is a 16550A Mar 08 09:17:28 localhost kernel: printk: console [ttyS0] enabled – Subject: A start job for unit getty@tty1.service has finished successfully – A start job for unit getty@tty1.service has finished successfully. – Subject: A start job for unit getty.target has finished successfully – A start job for unit getty.target has finished successfully. As can be seen, ttyS0 is enabled too late. Because of this, the getty service generator (systemd-getty-generator) does not create getty@ttyS0.service. I have seen a similar problem on RHEL 8 and filed a bug report for it: MMIO-based serial port does not work during the installation but works later https://bugzilla.redhat.com/show_bug.cgi?id=2162741 The behavior on RHEL 9 is better, since it is still possible to install the OS. It's possible to circumvent the problem by enabling the service explicitly: systemctl enable --now serial-getty@ttyS0.service

Release Notes

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Resolution

Unresolved