On 09/05/2014 13:01, Boris BREZILLON : > The sam9g25 and sam9g35 have the following errata:
Cf. below... > "RTC: Interrupt Mask Register cannot be used > Interrupt Mask Register read always returns 0." > > Hence we should not rely on what IMR claims about already masked irqs > and just disable all the IRQs. > > Cc: Andrew Morton <[email protected]> > Cc: <[email protected]> # v3.10+ > Signed-off-by: Boris BREZILLON <[email protected]> > --- > Hello, > > Sorry for the noise, I just forgot to remove the mask variable in my > previous version. > > Best Regards, > > Boris > > Changes since v2: > - removed unused variable 'mask' > Changes since v1: > - use a macro to define IRQs bitmask > - read IMR register to ensure the write to IDR has been flushed > - quote atmel's datasheet errata in commit message > - comment the code to describe why we're not using IMR to disable > the interrupts > > arch/arm/mach-at91/sysirq_mask.c | 22 +++++++++++++--------- > 1 file changed, 13 insertions(+), 9 deletions(-) > > diff --git a/arch/arm/mach-at91/sysirq_mask.c > b/arch/arm/mach-at91/sysirq_mask.c > index 2ba694f..1527dda 100644 > --- a/arch/arm/mach-at91/sysirq_mask.c > +++ b/arch/arm/mach-at91/sysirq_mask.c > @@ -25,24 +25,28 @@ > > #include "generic.h" > > -#define AT91_RTC_IDR 0x24 /* Interrupt Disable Register */ > -#define AT91_RTC_IMR 0x28 /* Interrupt Mask Register */ > +#define AT91_RTC_IDR 0x24 /* Interrupt Disable Register */ > +#define AT91_RTC_IMR 0x28 /* Interrupt Mask Register */ > +#define AT91_RTC_IRQ_MASK 0x1f /* Available IRQs mask */ > > void __init at91_sysirq_mask_rtc(u32 rtc_base) > { > void __iomem *base; > - u32 mask; > > base = ioremap(rtc_base, 64); > if (!base) > return; > > - mask = readl_relaxed(base + AT91_RTC_IMR); > - if (mask) { > - pr_info("AT91: Disabling rtc irq\n"); > - writel_relaxed(mask, base + AT91_RTC_IDR); > - (void)readl_relaxed(base + AT91_RTC_IMR); /* flush */ > - } > + /* > + * The sam9g25 and sam9g35 have the following errata: Actually all chips in what we call the "5 series" or "sam9x5" (sam9g15, sam9g25, sam9x25, sam9g35 and sam9x35). And... no, the sam9g45 is not part of that series ;-) > + * "RTC: Interrupt Mask Register cannot be used > + * Interrupt Mask Register read always returns 0." > + * > + * Hence we're not relying on IMR values to disable > + * interrupts. > + */ > + writel_relaxed(AT91_RTC_IRQ_MASK, base + AT91_RTC_IDR); > + (void)readl_relaxed(base + AT91_RTC_IMR); /* flush */ > > iounmap(base); > } Okay for me (maybe change the comment as it can puzzle some users): Acked-by: Nicolas Ferre <[email protected]> Thanks, bye, -- Nicolas Ferre -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
