From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: [PATCH] gpio/omap: fix off-mode bug: clear debounce clock enable mask on disable Date: Wed, 24 Oct 2012 10:39:27 +0300 Message-ID: <20121024073927.GC5665@arwen.pp.htv.fi> References: <1351015771-6308-1-git-send-email-khilman@deeprootsystems.com> <20121023190914.GA853@arwen.pp.htv.fi> <87k3ug7st2.fsf@deeprootsystems.com> Reply-To: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="TYecfFk8j8mZq+dy" Return-path: Received: from arroyo.ext.ti.com ([192.94.94.40]:59191 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934430Ab2JXHpO (ORCPT ); Wed, 24 Oct 2012 03:45:14 -0400 Content-Disposition: inline In-Reply-To: <87k3ug7st2.fsf@deeprootsystems.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Kevin Hilman Cc: balbi@ti.com, Linus Walleij , linux-omap@vger.kernel.org, Paul Walmsley , linux-arm-kernel@lists.infradead.org, Igor Grinberg --TYecfFk8j8mZq+dy Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Oct 23, 2012 at 03:00:09PM -0700, Kevin Hilman wrote: > Felipe Balbi writes: >=20 > > Hi, > > > > On Tue, Oct 23, 2012 at 11:09:31AM -0700, Kevin Hilman wrote: > >> From: Kevin Hilman > >>=20 > >> 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. > >>=20 > >> This was discovered when board code was doing > >>=20 > >> gpio_request_one() > >> gpio_set_debounce() > >> gpio_free() > >>=20 > >> 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. > >>=20 > >> Reported-by: Paul Walmsley > >> Cc: Igor Grinberg > >> Signed-off-by: Kevin Hilman > > > > looks like this deserves a Cc: stable@vger.kernel.org tag. > > >=20 > 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. >=20 > Linus, feel free to add the Cc: stable when commiting. Thanks. >=20 > >> --- > >> Applies on v3.7-rc2, targetted for v3.7. > >>=20 > >> drivers/gpio/gpio-omap.c | 1 + > >> 1 file changed, 1 insertion(+) > >>=20 > >> 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 =3D 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); > > =20 > > - 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. >=20 > 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. >=20 > > No strong feelings though. >=20 > Good. I'll take that as an Ack. :) please do: Acked-by: Felipe Balbi --=20 balbi --TYecfFk8j8mZq+dy Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJQh5svAAoJEIaOsuA1yqRE+90P/3tJIXDUgzQvrz4GdjOOSJlV q3Th5s7pJg8H+211RbDlLnHDVIoRZAta3l50f40JD3QvWBCfMLnAh+2bZaRX70we iO6wAXv/xQ+MRrReX30Pt8pEQ2B64XpGw3lHGzIEHYstpRbcbv5ZDoD8K9Shj5MC v4rAHQ5iF0ScvbiYAFi/0RZWocrzQS8um6No4FURGMwuZKZ/vZADnVhksGH0t+JM 7ufTpX+z9i60CqYkBbW2ghkUCeAaynywVVLEfP4n/SjQ5MDJzcylTOSyVNxPzHvw oYXalkl+mQ0clUfA87Xv0jAfwSiCv3dfdlzgeuEDpcJ0hkQ14Qmj+LxHfqHofU24 Bs956MEkTBGhj/sKK2+0xvEBn72J5c1/W37YqLS9HQt/ZHO2ZikrqTIZHF/YiN4t yv1EaLerMW/Cp6BSgfga39N6Sslr7smd21AKj3683GH4nsmA+PTRN++TsR/dqH2r 6ioEm2uh3bIuATuBNqlGP0FIbZ79aKKAi4VNp1Hehjk1fre/n2u3Vk2dx3LJWBGJ 8mJOg/YiFgwNt37Wrx6jT3LDqQWcmdyabcm3fGKJyeQZCkT7frlwFgFstQpBvgBg Hy7hHvgF09PXoOMJ/46QeTD7zajzjr1jAH4x1zT1ebA8id9i/eCYlQ87S1xfDteE 2Y6mYJBRq5s1wZpDDHFM =gUiC -----END PGP SIGNATURE----- --TYecfFk8j8mZq+dy-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: balbi@ti.com (Felipe Balbi) Date: Wed, 24 Oct 2012 10:39:27 +0300 Subject: [PATCH] gpio/omap: fix off-mode bug: clear debounce clock enable mask on disable In-Reply-To: <87k3ug7st2.fsf@deeprootsystems.com> References: <1351015771-6308-1-git-send-email-khilman@deeprootsystems.com> <20121023190914.GA853@arwen.pp.htv.fi> <87k3ug7st2.fsf@deeprootsystems.com> Message-ID: <20121024073927.GC5665@arwen.pp.htv.fi> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tue, Oct 23, 2012 at 03:00:09PM -0700, Kevin Hilman wrote: > Felipe Balbi writes: > > > Hi, > > > > On Tue, Oct 23, 2012 at 11:09:31AM -0700, Kevin Hilman wrote: > >> From: Kevin Hilman > >> > >> 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 > >> Cc: Igor Grinberg > >> Signed-off-by: Kevin Hilman > > > > looks like this deserves a Cc: stable at 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 -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: