This is a note to let you know that I've just added the patch titled hvsi: don't panic on tty_register_driver failure to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: hvsi-don-t-panic-on-tty_register_driver-failure.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit bd7a4844586b96efa67a1003c8e4b06c6d1aa2a4 Author: Jiri Slaby <jirislaby@xxxxxxxxxx> Date: Fri Jul 23 09:43:11 2021 +0200 hvsi: don't panic on tty_register_driver failure [ Upstream commit 7ccbdcc4d08a6d7041e4849219bbb12ffa45db4c ] The alloc_tty_driver failure is handled gracefully in hvsi_init. But tty_register_driver is not. panic is called if that one fails. So handle the failure of tty_register_driver gracefully too. This will keep at least the console functional as it was enabled earlier by console_initcall in hvsi_console_init. Instead of shooting down the whole system. This means, we disable interrupts and restore hvsi_wait back to poll_for_state(). Cc: linuxppc-dev@xxxxxxxxxxxxxxxx Signed-off-by: Jiri Slaby <jslaby@xxxxxxx> Link: https://lore.kernel.org/r/20210723074317.32690-3-jslaby@xxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c index 66f95f758be0..73226337f561 100644 --- a/drivers/tty/hvc/hvsi.c +++ b/drivers/tty/hvc/hvsi.c @@ -1038,7 +1038,7 @@ static const struct tty_operations hvsi_ops = { static int __init hvsi_init(void) { - int i; + int i, ret; hvsi_driver = alloc_tty_driver(hvsi_count); if (!hvsi_driver) @@ -1069,12 +1069,25 @@ static int __init hvsi_init(void) } hvsi_wait = wait_for_state; /* irqs active now */ - if (tty_register_driver(hvsi_driver)) - panic("Couldn't register hvsi console driver\n"); + ret = tty_register_driver(hvsi_driver); + if (ret) { + pr_err("Couldn't register hvsi console driver\n"); + goto err_free_irq; + } printk(KERN_DEBUG "HVSI: registered %i devices\n", hvsi_count); return 0; +err_free_irq: + hvsi_wait = poll_for_state; + for (i = 0; i < hvsi_count; i++) { + struct hvsi_struct *hp = &hvsi_ports[i]; + + free_irq(hp->virq, hp); + } + tty_driver_kref_put(hvsi_driver); + + return ret; } device_initcall(hvsi_init);