Hello Sebastian, Thanks a lot for your patch. On Thu, Feb 12, 2015 at 5:10 PM, Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> wrote: > This patch converts gpio_bank.lock from a spin_lock into a > raw_spin_lock. The call path to access this lock is always under a > raw_spin_lock, for instance > - __setup_irq() holds &desc->lock with irq off > + __irq_set_trigger() > + omap_gpio_irq_type() > > - handle_level_irq() (runs with irqs off therefore raw locks) > + mask_ack_irq() > + omap_gpio_mask_irq() > Agreed that raw_spin_lock should be used instead of spin_lock since afaiu those are converted to a rt-mutex in PREEMPT_RT and so they might sleep. > This fixes the obvious backtrace on -RT. However I noticed two cases > where it looks wrong and this is not limited to -RT: > - omap_gpio_irq_type() is called with IRQ off and has an conditional > call to pm_runtime_get_sync() which may sleep. Either it may happen or > it may not happen but pm_runtime_get_sync() should not be called in an > atomic section. > > - omap_gpio_debounce() is holding the lock with IRQs off. > + omap2_set_gpio_debounce() > + clk_prepare_enable() > + clk_prepare() this one might sleep. > The number of users of gpiod_set_debounce() / gpio_set_debounce() > looks low but still this is not good. > Right, those are bugs regardless of PREEMPT_RT or not as you said. I'll add it to my TODO list, thanks for finding those. > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> > --- > drivers/gpio/gpio-omap.c | 78 ++++++++++++++++++++++++------------------------ > 1 file changed, 39 insertions(+), 39 deletions(-) > Acked-by: Javier Martinez Canillas <javier@xxxxxxxxxxxx> Best regards, Javier -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
