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@lists.ozlabs.org
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210723074317.32690-3-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c
index 96ce6bd1cc6f699260b5b9613487d352cab57c08..4b6f93067ae4909318aac9756645873f96b9cf83 100644 (file)
--- a/drivers/tty/hvc/hvsi.c
+++ b/drivers/tty/hvc/hvsi.c
@@ -1051,7 +1051,7 @@ 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)
@@ -1082,12 +1082,25 @@ 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);