Re: [PATCH V2 1/2] tty/hvc: Use IRQF_SHARED for OPAL hvc consoles

On Tue, Jul 26, 2016 at 02:11:11PM +1000, Michael Ellerman wrote:

Quoting Michael Ellerman (2016-07-11 16:29:20)

quoted

Samuel Mendoza-Jonas [off-list ref] writes:

quoted

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:

[   51.179907] genirq: Flags mismatch irq 31. 00000000 (hvc_console) vs.
00000000 (hvc_console)
[   51.180010] 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>
Cc: <redacted> # 4.1.x-
---
 drivers/tty/hvc/hvc_console.h | 1 +
 drivers/tty/hvc/hvc_irq.c     | 7 +++++--
 drivers/tty/hvc/hvc_opal.c    | 3 +++
 3 files changed, 9 insertions(+), 2 deletions(-)

Acked-by: Michael Ellerman <mpe@ellerman.id.au>

Greg are you happy to take these two?

Hi Greg,

I don't see this series anywhere, do you mind if I take them via the
powerpc tree for 4.8 ? Or do you want to pick them up.

You can take them, I'm not touching patches now until 4.8-rc1 is out,
sorry.

thanks,

greg k-h