tty: serial: add missing spin_lock_init for SiFive serial console

commit 17b4efdf4e4867079012a48ca10d965fe9d68822 upstream.

An uninitialised spin lock for sifive serial console raises a bad
magic spin_lock error as reported and discussed here [1].
Initialising the spin lock resolves the issue.

The fix is tested on HiFive Unleashed A00 board with Linux 5.7-rc4
and OpenSBI v0.7

[1] https://lore.kernel.org/linux-riscv/b9fe49483a903f404e7acc15a6efbef756db28ae.camel@wdc.com

Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART")
Reported-by: Atish Patra <Atish.Patra@wdc.com>
Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1589019852-21505-2-git-send-email-sagar.kadam@sifive.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c
index d5f81b9..38133eb 100644 (file)
--- a/drivers/tty/serial/sifive.c
+++ b/drivers/tty/serial/sifive.c
@@ -840,6 +840,7 @@ console_initcall(sifive_console_init);
 
 static void __ssp_add_console_port(struct sifive_serial_port *ssp)
 {
+       spin_lock_init(&ssp->port.lock);
        sifive_serial_console_ports[ssp->port.line] = ssp;
 }