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: Tue, 23 Oct 2012 22:09:14 +0300 Message-ID: <20121023190914.GA853@arwen.pp.htv.fi> References: <1351015771-6308-1-git-send-email-khilman@deeprootsystems.com> Reply-To: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="RnlQjJ0d97Da+TV1" Return-path: Received: from bear.ext.ti.com ([192.94.94.41]:38507 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932144Ab2JWTPe (ORCPT ); Tue, 23 Oct 2012 15:15:34 -0400 Content-Disposition: inline In-Reply-To: <1351015771-6308-1-git-send-email-khilman@deeprootsystems.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Kevin Hilman Cc: Linus Walleij , Felipe Balbi , linux-omap@vger.kernel.org, Paul Walmsley , linux-arm-kernel@lists.infradead.org, Igor Grinberg --RnlQjJ0d97Da+TV1 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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. > --- > 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_ban= k *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_ban= k *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. No strong feelings though. --=20 balbi --RnlQjJ0d97Da+TV1 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJQhutaAAoJEIaOsuA1yqREi/gP/0Y/hJIOBYmRolURQiIFtLuD qhfIsSyrO8BirBt2rD5HVhYxEfBBDvbvhy3kWCysHvRINllTNVE0BFeBzAYusObP IFzymivwcgvm4/pHrAF1OrjA7skXkEL8QtwUqqVzd1I+puVfSsyjpQ3BWWRGAWT+ +g/5YlE/mgIQ+1OFzMygy5dtVK/Visxw858pLpoFnCtKQVKBbDWVarZE5kqJHSAV 5gvLqtbqdb3A4fc202vAPinXzvCP3ehuzMlWqqrLZRX4E1uPHN5S7dmx4EdzdNMA MOTNgcLYWSOAzr1KU9gM924hGadlBOWcaV8e9GkKo+j94nN6GrGIW3TNM/9N3jhB xZPG+onjH10rLUKJSoweZR0ErT+WYFzZZeSNfQ0cZkrLGYSEVxUI589DmglgIxVI QDOL0DJJwC7z6X2CNDCGIp7Uj938c+rjmucm8/KpIRiUgk0/X2/BQDmbzlWKKnAf IUHQ4SRR3fwXQ7WpfvO3vQ8jAUNqsi7e3eIfWvjS4+1X65mQNX5+h9oeEkoO2hFJ rPCp9TzNGByjAuGK+92NWFlbavJ50PX1h5QRngRQOkzlG9tkBKbNP+xouTzeh7VY Onr65JzaXQ4QMcp8ozPmjdeaHdyqzBt00iRtlu7mxjbwGqas7aiNlhZHxUX6A9A4 bFu8W9VE3KUMKsblNjDY =0INv -----END PGP SIGNATURE----- --RnlQjJ0d97Da+TV1-- From mboxrd@z Thu Jan 1 00:00:00 1970 From: balbi@ti.com (Felipe Balbi) Date: Tue, 23 Oct 2012 22:09:14 +0300 Subject: [PATCH] gpio/omap: fix off-mode bug: clear debounce clock enable mask on disable In-Reply-To: <1351015771-6308-1-git-send-email-khilman@deeprootsystems.com> References: <1351015771-6308-1-git-send-email-khilman@deeprootsystems.com> Message-ID: <20121023190914.GA853@arwen.pp.htv.fi> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. > --- > 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. No strong feelings though. -- balbi -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 836 bytes Desc: Digital signature URL: