[PATCH -next] irqchip/imx-intmux: Fix irqdata regs save in imx_intmux_runtime_suspend()

[Joakim Zhang]

> -----Original Message-----
> From: Marc Zyngier <maz at kernel.org>
> Sent: 2020年7月30日 1:00
> To: Wei Yongjun <weiyongjun1 at huawei.com>
> Cc: Hulk Robot <hulkci at huawei.com>; Thomas Gleixner <tglx at linutronix.de>;
> Jason Cooper <jason at lakedaemon.net>; Shawn Guo <shawnguo at kernel.org>;
> Sascha Hauer <s.hauer at pengutronix.de>; Joakim Zhang
> <qiangqing.zhang at nxp.com>; linux-arm-kernel at lists.infradead.org;
> linux-kernel at vger.kernel.org
> Subject: Re: [PATCH -next] irqchip/imx-intmux: Fix irqdata regs save in
> imx_intmux_runtime_suspend()
> 
> On 2020-07-29 16:58, Wei Yongjun wrote:
> > Gcc report warning as follows:
> >
> > drivers/irqchip/irq-imx-intmux.c:316:29: warning:
> >  variable 'irqchip_data' set but not used [-Wunused-but-set-variable]
> >   316 |  struct intmux_irqchip_data irqchip_data;
> >       |                             ^~~~~~~~~~~~
> >
> > irqdata regs is stored to this variable on the stack in
> > imx_intmux_runtime_suspend(), which means a nop. this commit fix to
> > save regs to the right place.
> >
> > Fixes: bb403111e017 ("irqchip/imx-intmux: Implement intmux runtime
> > power management")
> > Reported-by: Hulk Robot <hulkci at huawei.com>
> > Signed-off-by: Wei Yongjun <weiyongjun1 at huawei.com>
> > ---
> >  drivers/irqchip/irq-imx-intmux.c | 12 ++++++------
> >  1 file changed, 6 insertions(+), 6 deletions(-)

[...]
> Amazing. Thanks for fixing this.
> 
> Johakim: I guess this was never tested, was it?


Hi Marc,

Firstly, thanks Wei Yongjun for fixing this.

I do the intmux function test for each version.

At my side, I test intmux with CAN device. This intmux in M4 core subsystem, devices located in M4 core subsystem will route irqs into intmux.
CAN transceiver is controlled by an I/O expander which is lined to I2C from M4 core subsystem. And CAN device is located in A35 core subsystem.

After implementing runtime pm, I test CAN work fine when do suspend/resume test and I check the runtime status. I guess intmux register's state will not lost in M4 core subsystem when system suspended.

However, this is a silly mistake, I am so sorry for this.

Best Regards,
Joakim Zhang
>          M.
> --
> Jazz is not dead. It just smells funny...