tty/hvc: Use IRQF_SHARED for OPAL hvc consoles
Commit 2def86a7200c ("hvc: Convert to using interrupts instead of opal
events") enabled the use of interrupts in the hvc_driver for OPAL
platforms. However on machines with more than one hvc console, any
console after the first will fail to register an interrupt handler in
notifier_add_irq() since all consoles share the same IRQ number but do
not set the IRQF_SHARED flag:
genirq: Flags mismatch irq 31. 00000000 (hvc_console) vs. 00000000 (hvc_console)
hvc_open: request_irq failed with rc -16.
This error propagates up to hvc_open() and the console is closed, but
OPAL will still generate interrupts that are not handled, leading to
rcu_sched stall warnings.
Set IRQF_SHARED when calling request_irq(), allowing additional consoles
to start properly. This is only set for consoles handled by
hvc_opal_probe(), leaving other types unaffected.
Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/drivers/tty/hvc/hvc_irq.c b/drivers/tty/hvc/hvc_irq.c
index c9adb05..bc7a968 100644
--- a/drivers/tty/hvc/hvc_irq.c
+++ b/drivers/tty/hvc/hvc_irq.c
@@ -14,6 +14,11 @@
/* if hvc_poll request a repoll, then kick the hvcd thread */
if (hvc_poll(dev_instance))
hvc_kick();
+
+ /*
+ * We're safe to always return IRQ_HANDLED as the hvcd thread will
+ * iterate through each hvc_struct.
+ */
return IRQ_HANDLED;
}
@@ -28,8 +33,8 @@
hp->irq_requested = 0;
return 0;
}
- rc = request_irq(irq, hvc_handle_interrupt, 0,
- "hvc_console", hp);
+ rc = request_irq(irq, hvc_handle_interrupt, hp->flags,
+ "hvc_console", hp);
if (!rc)
hp->irq_requested = 1;
return rc;