From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roger Quadros Subject: Re: [PATCH v4 04/12] gpio/omap: remove saved_wakeup field from struct gpio_bank Date: Mon, 9 Jul 2012 14:51:50 +0300 Message-ID: <4FFAC5D6.4090306@ti.com> References: <1331906760-5259-1-git-send-email-tarun.kanti@ti.com> <1331906760-5259-5-git-send-email-tarun.kanti@ti.com> <4FFAA7B3.6020009@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: Received: from bear.ext.ti.com ([192.94.94.41]:51761 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753239Ab2GILwC (ORCPT ); Mon, 9 Jul 2012 07:52:02 -0400 In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "DebBarma, Tarun Kanti" Cc: linux-omap@vger.kernel.org, khilman@ti.com, tony@atomide.com, b-cousson@ti.com, grant.likely@secretlab.ca, linux-arm-kernel@lists.infradead.org Tarun, On 07/09/2012 02:16 PM, DebBarma, Tarun Kanti wrote: > Hi Roger, > > On Mon, Jul 9, 2012 at 3:13 PM, Roger Quadros wrote: >> Hi, >> >> Just bumped across this patch and have a query. >> >> On 03/16/2012 04:05 PM, Tarun Kanti DebBarma wrote: >>> There is no more need to have saved_wakeup because bank->context.wake_en >>> already holds that value. So getting rid of read/write operation associated >>> with this field. >>> >>> Signed-off-by: Tarun Kanti DebBarma >>> Reviewed-by: Santosh Shilimkar >>> Acked-by: Felipe Balbi >>> --- >>> drivers/gpio/gpio-omap.c | 12 +++--------- >>> 1 files changed, 3 insertions(+), 9 deletions(-) >>> >>> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c >>> index 3a4f151..3b91ade 100644 >>> --- a/drivers/gpio/gpio-omap.c >>> +++ b/drivers/gpio/gpio-omap.c >>> @@ -57,7 +57,6 @@ struct gpio_bank { >>> u16 irq; >>> int irq_base; >>> struct irq_domain *domain; >>> - u32 saved_wakeup; >>> u32 non_wakeup_gpios; >>> u32 enabled_non_wakeup_gpios; >>> struct gpio_regs context; >>> @@ -777,7 +776,6 @@ static int omap_mpuio_suspend_noirq(struct device *dev) >>> unsigned long flags; >>> >>> spin_lock_irqsave(&bank->lock, flags); >>> - bank->saved_wakeup = __raw_readl(mask_reg); >>> __raw_writel(0xffff & ~bank->context.wake_en, mask_reg); >> >> OK, here you are overwriting the mask_reg with the wakeup bitmask >> without saving the mask_reg's original content. > This is based upon understanding that set_gpio_trigger() is the common > function where update of wake_en register takes place. Unless, mask_reg > in this case refers to something else, effectively we would be saving the > same value to saved_wakeup what is already present in wake_en. > I will verify this specific to this function. > >> >>> spin_unlock_irqrestore(&bank->lock, flags); >>> >>> @@ -793,7 +791,7 @@ static int omap_mpuio_resume_noirq(struct device *dev) >>> unsigned long flags; >>> >>> spin_lock_irqsave(&bank->lock, flags); >>> - __raw_writel(bank->saved_wakeup, mask_reg); >>> + __raw_writel(bank->context.wake_en, mask_reg); >> >> Now you are restoring nothing but the same content that you stored >> during suspend. This will cause the non-wakeup gpio interrupts to get >> masked between a suspend/resume. So isn't this a bug? > That's right, the same value is restored back which was last updated in > set_gpio_trigger() that got stored in wake_en register. Let me know if > I am missing your points here. If it is writing the same thing then isn't this write redundant? > >> >> Proper solution would be to save the mask_reg context into another >> register than context.wake_en during suspend. > As I said, this would make sense if mask_reg is referring to different > register than what is used in set_gpio_trigger(). I will have a look. OK thanks. > > BTW, did you observe anything unusual during some testing? No, I haven't done any tests. cheers, -roger From mboxrd@z Thu Jan 1 00:00:00 1970 From: rogerq@ti.com (Roger Quadros) Date: Mon, 9 Jul 2012 14:51:50 +0300 Subject: [PATCH v4 04/12] gpio/omap: remove saved_wakeup field from struct gpio_bank In-Reply-To: References: <1331906760-5259-1-git-send-email-tarun.kanti@ti.com> <1331906760-5259-5-git-send-email-tarun.kanti@ti.com> <4FFAA7B3.6020009@ti.com> Message-ID: <4FFAC5D6.4090306@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Tarun, On 07/09/2012 02:16 PM, DebBarma, Tarun Kanti wrote: > Hi Roger, > > On Mon, Jul 9, 2012 at 3:13 PM, Roger Quadros wrote: >> Hi, >> >> Just bumped across this patch and have a query. >> >> On 03/16/2012 04:05 PM, Tarun Kanti DebBarma wrote: >>> There is no more need to have saved_wakeup because bank->context.wake_en >>> already holds that value. So getting rid of read/write operation associated >>> with this field. >>> >>> Signed-off-by: Tarun Kanti DebBarma >>> Reviewed-by: Santosh Shilimkar >>> Acked-by: Felipe Balbi >>> --- >>> drivers/gpio/gpio-omap.c | 12 +++--------- >>> 1 files changed, 3 insertions(+), 9 deletions(-) >>> >>> diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c >>> index 3a4f151..3b91ade 100644 >>> --- a/drivers/gpio/gpio-omap.c >>> +++ b/drivers/gpio/gpio-omap.c >>> @@ -57,7 +57,6 @@ struct gpio_bank { >>> u16 irq; >>> int irq_base; >>> struct irq_domain *domain; >>> - u32 saved_wakeup; >>> u32 non_wakeup_gpios; >>> u32 enabled_non_wakeup_gpios; >>> struct gpio_regs context; >>> @@ -777,7 +776,6 @@ static int omap_mpuio_suspend_noirq(struct device *dev) >>> unsigned long flags; >>> >>> spin_lock_irqsave(&bank->lock, flags); >>> - bank->saved_wakeup = __raw_readl(mask_reg); >>> __raw_writel(0xffff & ~bank->context.wake_en, mask_reg); >> >> OK, here you are overwriting the mask_reg with the wakeup bitmask >> without saving the mask_reg's original content. > This is based upon understanding that set_gpio_trigger() is the common > function where update of wake_en register takes place. Unless, mask_reg > in this case refers to something else, effectively we would be saving the > same value to saved_wakeup what is already present in wake_en. > I will verify this specific to this function. > >> >>> spin_unlock_irqrestore(&bank->lock, flags); >>> >>> @@ -793,7 +791,7 @@ static int omap_mpuio_resume_noirq(struct device *dev) >>> unsigned long flags; >>> >>> spin_lock_irqsave(&bank->lock, flags); >>> - __raw_writel(bank->saved_wakeup, mask_reg); >>> + __raw_writel(bank->context.wake_en, mask_reg); >> >> Now you are restoring nothing but the same content that you stored >> during suspend. This will cause the non-wakeup gpio interrupts to get >> masked between a suspend/resume. So isn't this a bug? > That's right, the same value is restored back which was last updated in > set_gpio_trigger() that got stored in wake_en register. Let me know if > I am missing your points here. If it is writing the same thing then isn't this write redundant? > >> >> Proper solution would be to save the mask_reg context into another >> register than context.wake_en during suspend. > As I said, this would make sense if mask_reg is referring to different > register than what is used in set_gpio_trigger(). I will have a look. OK thanks. > > BTW, did you observe anything unusual during some testing? No, I haven't done any tests. cheers, -roger