On 01. 02. 24, 7:59, Andy Chiu wrote:
It is not safe to call spin_lock() with irq disabled on RT-linux.
Instead, transfer the code segment to spin_lock_irqsave to make it work
on both RT and non-RT linux.
Hi,
have you investigated what is protected by the local_irq_save() in
there? The lock is not always taken, OTOH the interrupts are always
disabled.
I believe the fix is not as easy as is presented below.
Signed-off-by: Andy Chiu <andy.chiu@xxxxxxxxxx>
---
drivers/tty/serial/sifive.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c
index fa4c9336924f..3f0ddf8bfa7b 100644
--- a/drivers/tty/serial/sifive.c
+++ b/drivers/tty/serial/sifive.c
@@ -788,13 +788,12 @@ static void sifive_serial_console_write(struct console *co, const char *s,
if (!ssp)
return;
- local_irq_save(flags);
if (ssp->port.sysrq)
locked = 0;
else if (oops_in_progress)
- locked = spin_trylock(&ssp->port.lock);
+ locked = spin_trylock_irqsave(&ssp->port.lock, flags);
else
- spin_lock(&ssp->port.lock);
+ spin_lock_irqsave(&ssp->port.lock, flags);
ier = __ssp_readl(ssp, SIFIVE_SERIAL_IE_OFFS);
__ssp_writel(0, SIFIVE_SERIAL_IE_OFFS, ssp);
@@ -804,8 +803,7 @@ static void sifive_serial_console_write(struct console *co, const char *s,
__ssp_writel(ier, SIFIVE_SERIAL_IE_OFFS, ssp);
if (locked)
- spin_unlock(&ssp->port.lock);
- local_irq_restore(flags);
+ spin_unlock_irqrestore(&ssp->port.lock, flags);
}
static int __init sifive_serial_console_setup(struct console *co, char *options)
--
js
suse labs
