If an edge interrupt triggers while entering idle just before we save GPIO datain register to saved_datain, the triggered GPIO will not be noticed on wake-up. This is because the saved_datain and GPIO datain are the same. Let's fix this by ignoring any pending edge interrupts in saved_datain. This can be somewhat easily reproduced by pinging an idle system with smsc911x Ethernet interface configured IRQ_TYPE_EDGE_FALLING. At some point the smsc911x interrupts will just stop triggering. Note that in the long run we may be able to cancel entering idle by returning an error in gpio_omap_cpu_notifier(). But let's fix the bug first. Also note that because of the recent clean-up efforts this patch does not apply directly to older kernels. This does fix a long term issue though, and can be backported as needed. Cc: Aaro Koskinen <aaro.koskinen@xxxxxx> Cc: Grygorii Strashko <grygorii.strashko@xxxxxx> Cc: Keerthy <j-keerthy@xxxxxx> Cc: Ladislav Michl <ladis@xxxxxxxxxxxxxx> Cc: Peter Ujfalusi <peter.ujfalusi@xxxxxx> Cc: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> Cc: Tero Kristo <t-kristo@xxxxxx> Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx> --- drivers/gpio/gpio-omap.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c --- a/drivers/gpio/gpio-omap.c +++ b/drivers/gpio/gpio-omap.c @@ -1279,7 +1279,14 @@ static void omap_gpio_idle(struct gpio_bank *bank, bool may_lose_context) void __iomem *base = bank->base; u32 nowake; + /* + * Save datain register to trigger edge interrupts on unidle for GPIOS + * that are not wake-up capable. Ignore any enabled_non_wakeup_gpios + * that may have just triggered as we're entering idle. Otherwise unidle + * will not notice them. + */ bank->saved_datain = readl_relaxed(base + bank->regs->datain); + bank->saved_datain |= bank->enabled_non_wakeup_gpios; if (!bank->enabled_non_wakeup_gpios) goto update_gpio_context_count; -- 2.21.0
