| Message ID | 20121023190914.GA853@arwen.pp.htv.fi (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Felipe Balbi <balbi@ti.com> writes: > Hi, > > On Tue, Oct 23, 2012 at 11:09:31AM -0700, Kevin Hilman wrote: >> From: Kevin Hilman <khilman@ti.com> >> >> When debounce clocks are disabled, ensure that the banks >> dbck_enable_mask is cleared also. Otherwise, context restore on >> subsequent off-mode transition will restore previous value from the >> shadow copies (bank->context.debounce*) leading to mismatch state >> between driver state and hardware state. >> >> This was discovered when board code was doing >> >> gpio_request_one() >> gpio_set_debounce() >> gpio_free() >> >> which was leaving the GPIO debounce settings in a confused state. >> Then, enabling off mode causing bogus state to be restored, leaving >> GPIO debounce enabled which then prevented the CORE powerdomain from >> transitioning. >> >> Reported-by: Paul Walmsley <paul@pwsan.com> >> Cc: Igor Grinberg <grinberg@compulab.co.il> >> Signed-off-by: Kevin Hilman <khilman@ti.com> > > looks like this deserves a Cc: stable@vger.kernel.org tag. > Agreed. I think this goes all the way back to v3.5, but would've only been seen on boards using a request/gpio_set_debounce/free sequence combined with off-mode. Linus, feel free to add the Cc: stable when commiting. Thanks. >> --- >> Applies on v3.7-rc2, targetted for v3.7. >> >> drivers/gpio/gpio-omap.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c >> index 94cbc84..dee2856 100644 >> --- a/drivers/gpio/gpio-omap.c >> +++ b/drivers/gpio/gpio-omap.c >> @@ -187,6 +187,7 @@ static inline void _gpio_dbck_disable(struct gpio_bank *bank) >> * to detect events and generate interrupts at least on OMAP3. >> */ >> __raw_writel(0, bank->base + bank->regs->debounce_en); >> + bank->dbck_enable_mask = 0; > > shouldn't omap_gpio_restore_context() check for dbck_enabled instead of > the mask ? I mean: > > diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c > index 94cbc84..b3a39a7 100644 > --- a/drivers/gpio/gpio-omap.c > +++ b/drivers/gpio/gpio-omap.c > @@ -1371,7 +1371,7 @@ static void omap_gpio_restore_context(struct gpio_bank *bank) > bank->base + bank->regs->dataout); > __raw_writel(bank->context.oe, bank->base + bank->regs->direction); > > - if (bank->dbck_enable_mask) { > + if (bank->dbck_enabled) { > __raw_writel(bank->context.debounce, bank->base + > bank->regs->debounce); > __raw_writel(bank->context.debounce_en, > > the outcome would be the same, so it doesn't really matter. Just that, > at least to me, it would look better. I tried your version, and unfortunately, the outcome is not the same, but don't plan to look into why. $SUBJECT version is targetted and tested. If you want to cleanup the cosmetics here, please do in a subsequent patch. This driver could certainly benefit from more readability cleanups. > No strong feelings though. Good. I'll take that as an Ack. :) Kevin
On Tue, Oct 23, 2012 at 03:00:09PM -0700, Kevin Hilman wrote: > Felipe Balbi <balbi@ti.com> writes: > > > Hi, > > > > On Tue, Oct 23, 2012 at 11:09:31AM -0700, Kevin Hilman wrote: > >> From: Kevin Hilman <khilman@ti.com> > >> > >> When debounce clocks are disabled, ensure that the banks > >> dbck_enable_mask is cleared also. Otherwise, context restore on > >> subsequent off-mode transition will restore previous value from the > >> shadow copies (bank->context.debounce*) leading to mismatch state > >> between driver state and hardware state. > >> > >> This was discovered when board code was doing > >> > >> gpio_request_one() > >> gpio_set_debounce() > >> gpio_free() > >> > >> which was leaving the GPIO debounce settings in a confused state. > >> Then, enabling off mode causing bogus state to be restored, leaving > >> GPIO debounce enabled which then prevented the CORE powerdomain from > >> transitioning. > >> > >> Reported-by: Paul Walmsley <paul@pwsan.com> > >> Cc: Igor Grinberg <grinberg@compulab.co.il> > >> Signed-off-by: Kevin Hilman <khilman@ti.com> > > > > looks like this deserves a Cc: stable@vger.kernel.org tag. > > > > Agreed. I think this goes all the way back to v3.5, but would've only > been seen on boards using a request/gpio_set_debounce/free sequence > combined with off-mode. > > Linus, feel free to add the Cc: stable when commiting. Thanks. > > >> --- > >> Applies on v3.7-rc2, targetted for v3.7. > >> > >> drivers/gpio/gpio-omap.c | 1 + > >> 1 file changed, 1 insertion(+) > >> > >> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c > >> index 94cbc84..dee2856 100644 > >> --- a/drivers/gpio/gpio-omap.c > >> +++ b/drivers/gpio/gpio-omap.c > >> @@ -187,6 +187,7 @@ static inline void _gpio_dbck_disable(struct gpio_bank *bank) > >> * to detect events and generate interrupts at least on OMAP3. > >> */ > >> __raw_writel(0, bank->base + bank->regs->debounce_en); > >> + bank->dbck_enable_mask = 0; > > > > shouldn't omap_gpio_restore_context() check for dbck_enabled instead of > > the mask ? I mean: > > > > diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c > > index 94cbc84..b3a39a7 100644 > > --- a/drivers/gpio/gpio-omap.c > > +++ b/drivers/gpio/gpio-omap.c > > @@ -1371,7 +1371,7 @@ static void omap_gpio_restore_context(struct gpio_bank *bank) > > bank->base + bank->regs->dataout); > > __raw_writel(bank->context.oe, bank->base + bank->regs->direction); > > > > - if (bank->dbck_enable_mask) { > > + if (bank->dbck_enabled) { > > __raw_writel(bank->context.debounce, bank->base + > > bank->regs->debounce); > > __raw_writel(bank->context.debounce_en, > > > > the outcome would be the same, so it doesn't really matter. Just that, > > at least to me, it would look better. > > I tried your version, and unfortunately, the outcome is not the same, > but don't plan to look into why. $SUBJECT version is targetted and > tested. If you want to cleanup the cosmetics here, please do in a > subsequent patch. This driver could certainly benefit from more > readability cleanups. > > > No strong feelings though. > > Good. I'll take that as an Ack. :) please do: Acked-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c index 94cbc84..b3a39a7 100644 --- a/drivers/gpio/gpio-omap.c +++ b/drivers/gpio/gpio-omap.c @@ -1371,7 +1371,7 @@ static void omap_gpio_restore_context(struct gpio_bank *bank) bank->base + bank->regs->dataout); __raw_writel(bank->context.oe, bank->base + bank->regs->direction); - if (bank->dbck_enable_mask) { + if (bank->dbck_enabled) { __raw_writel(bank->context.debounce, bank->base + bank->regs->debounce); __raw_writel(bank->context.debounce_en,