Re: [PATCH v2 2/4] pinctrl: rockchip: convert to raw spinlock
From: Heiko Stuebner
Date: Wed Mar 15 2017 - 14:17:13 EST
Am Mittwoch, 15. März 2017, 18:08:06 CET schrieb John Keeping:
> On Wed, 15 Mar 2017 13:01:37 -0500, Julia Cartwright wrote:
> > On Wed, Mar 15, 2017 at 05:46:52PM +0000, John Keeping wrote:
> > > This lock is used from rockchip_irq_set_type() which is part of the
> > > irq_chip implementation and thus must use raw_spinlock_t as documented
> > > in Documentation/gpio/driver.txt.
> > >
> > > Signed-off-by: John Keeping <john@xxxxxxxxxxxx>
> > > Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>
> > > Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
> > > ---
> > > v2: unchanged
> > > ---
> > >
> > > drivers/pinctrl/pinctrl-rockchip.c | 30 +++++++++++++++---------------
> > > 1 file changed, 15 insertions(+), 15 deletions(-)
> > >
> > > diff --git a/drivers/pinctrl/pinctrl-rockchip.c
> > > b/drivers/pinctrl/pinctrl-rockchip.c index 128c383ea7ba..8c1cae6d78d7
> > > 100644
> > > --- a/drivers/pinctrl/pinctrl-rockchip.c
> > > +++ b/drivers/pinctrl/pinctrl-rockchip.c
> > > @@ -163,7 +163,7 @@ struct rockchip_pin_bank {
> > >
> > > struct irq_domain *domain;
> > > struct gpio_chip gpio_chip;
> > > struct pinctrl_gpio_range grange;
> > >
> > > - spinlock_t slock;
> > > + raw_spinlock_t slock;
> > >
> > > u32 toggle_edge_mode;
> > >
> > > };
> > >
> > > @@ -1295,14 +1295,14 @@ static int rockchip_set_pull(struct
> > > rockchip_pin_bank *bank,> >
> > > switch (ctrl->type) {
> > >
> > > case RK2928:
> > > - spin_lock_irqsave(&bank->slock, flags);
> > > + raw_spin_lock_irqsave(&bank->slock, flags);
> > >
> > > data = BIT(bit + 16);
> > > if (pull == PIN_CONFIG_BIAS_DISABLE)
> > >
> > > data |= BIT(bit);
> >
> > This should be lifted out from under the lock.
> >
> > > ret = regmap_write(regmap, reg, data);
> >
> > How is this legal? The regmap_write() here is going to end up acquiring
> > the regmap mutex.
>
> It's not, the spinlock can be deleted here. I only have RK3288 hardware
> to test and I missed this when checking the uses of slock.
That part could very well also use regmap_update_bits like the other parts.
Not really sure, why we use regmap_write here, but I'm also not sure, if it
matters at all.