| Message ID | 20190508181939.1990-1-tony@atomide.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | gpio: gpio-omap: Fix lost edge wake-up interrupts | expand |
* Tony Lindgren <tony@atomide.com> [190508 11:20]: > --- 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; Oops, sorry this is not complete yet. We need to enable or clear the possible pending interrupt in saved_datain based on the edge interrupt polarity. I'll fix and resend. Regards, Tony
* Tony Lindgren <tony@atomide.com> [190508 20:40]: > * Tony Lindgren <tony@atomide.com> [190508 11:20]: > > --- 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; > > Oops, sorry this is not complete yet. We need to enable or clear > the possible pending interrupt in saved_datain based on the edge > interrupt polarity. I'll fix and resend. Below seems to behave for me based on light testing.. Might be worth thinking about this a bit more, anybody got better ideas? :) Regards, Tony 8< -------------------- 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 @@ -1277,10 +1277,24 @@ static void omap_gpio_idle(struct gpio_bank *bank, bool may_lose_context) { struct device *dev = bank->chip.parent; void __iomem *base = bank->base; - u32 nowake; + u32 mask, 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. Note that this does not help with EDGE_BOTH. + */ bank->saved_datain = readl_relaxed(base + bank->regs->datain); + mask = bank->enabled_non_wakeup_gpios & bank->context.fallingdetect; + mask &= ~bank->context.risingdetect; + bank->saved_datain |= mask; + + mask = bank->enabled_non_wakeup_gpios & bank->context.risingdetect; + mask &= ~bank->context.fallingdetect; + bank->saved_datain &= ~mask; + if (!bank->enabled_non_wakeup_gpios) goto update_gpio_context_count;
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;
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@iki.fi> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Keerthy <j-keerthy@ti.com> Cc: Ladislav Michl <ladis@linux-mips.org> Cc: Peter Ujfalusi <peter.ujfalusi@ti.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Tero Kristo <t-kristo@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com> --- drivers/gpio/gpio-omap.c | 7 +++++++ 1 file changed, 7 insertions(+)