[PATCH] gpio: Langwell GPIO driver miscellaneous clean-ups

[PATCH] gpio: Langwell GPIO driver miscellaneous clean-ups

[Alek Du]

>From 9ba8224f5246ef7fdf1c0a15bb5535e442731435 Mon Sep 17 00:00:00 2001
From: Alek Du <alek.du@intel.com>
Date: Sun, 22 Nov 2009 10:58:21 +0800
Subject: [PATCH] gpio: Langwell GPIO driver miscellaneous clean-ups

1. Use >= N to check invalid gpio number (unsigned type)
2. Remove wrong and unnecessary unmask operation
3. Remove extra GEDR reading

The 2) and 3) will fix interrupts losing when two or more pins are triggered at close time.

Signed-off-by: Alek Du <alek.du@intel.com>
---
 drivers/gpio/langwell_gpio.c |   13 ++-----------
 1 files changed, 2 insertions(+), 11 deletions(-)

diff --git a/drivers/gpio/langwell_gpio.c b/drivers/gpio/langwell_gpio.c
index 5711ce5..6c0ebbd 100644
--- a/drivers/gpio/langwell_gpio.c
+++ b/drivers/gpio/langwell_gpio.c
@@ -123,7 +123,7 @@ static int lnw_irq_type(unsigned irq, unsigned type)
 	void __iomem *grer = (void __iomem *)(&lnw->reg_base->GRER[reg]);
 	void __iomem *gfer = (void __iomem *)(&lnw->reg_base->GFER[reg]);
 
-	if (gpio < 0 || gpio > lnw->chip.ngpio)
+	if (gpio >= lnw->chip.ngpio)
 		return -EINVAL;
 	spin_lock_irqsave(&lnw->lock, flags);
 	if (type & IRQ_TYPE_EDGE_RISING)
@@ -144,13 +144,6 @@ static int lnw_irq_type(unsigned irq, unsigned type)
 
 static void lnw_irq_unmask(unsigned irq)
 {
-	struct lnw_gpio *lnw = get_irq_chip_data(irq);
-	u32 gpio = irq - lnw->irq_base;
-	u8 reg = gpio / 32;
-	void __iomem *gedr;
-
-	gedr = (void __iomem *)(&lnw->reg_base->GEDR[reg]);
-	writel(BIT(gpio % 32), gedr);
 };
 
 static void lnw_irq_mask(unsigned irq)
@@ -183,13 +176,11 @@ static void lnw_irq_handler(unsigned irq, struct irq_desc *desc)
 		gedr_v = readl(gedr);
 		if (!gedr_v)
 			continue;
-		for (gpio = reg*32; gpio < reg*32+32; gpio++) {
-			gedr_v = readl(gedr);
+		for (gpio = reg*32; gpio < reg*32+32; gpio++)
 			if (gedr_v & BIT(gpio % 32)) {
 				pr_debug("pin %d triggered\n", gpio);
 				generic_handle_irq(lnw->irq_base + gpio);
 			}
-		}
 		/* clear the edge detect status bit */
 		writel(gedr_v, gedr);
 	}
-- 
1.6.3.3

Re: [PATCH] gpio: Langwell GPIO driver miscellaneous clean-ups

[Andrew Morton]

On Sun, 22 Nov 2009 11:19:01 +0800
Alek Du <alek.du@intel.com> wrote:

> >From 9ba8224f5246ef7fdf1c0a15bb5535e442731435 Mon Sep 17 00:00:00 2001
> From: Alek Du <alek.du@intel.com>
> Date: Sun, 22 Nov 2009 10:58:21 +0800
> Subject: [PATCH] gpio: Langwell GPIO driver miscellaneous clean-ups
> 
> 1. Use >= N to check invalid gpio number (unsigned type)

I already had this in gpio-fix-test-on-unsigned-in-lnw_irq_type.patch

> 2. Remove wrong and unnecessary unmask operation
> 3. Remove extra GEDR reading
> 
> The 2) and 3) will fix interrupts losing when two or more pins are triggered at close time.
> 

Those aren't cleanups - they're bug fixes!

How important are they?

Re: [PATCH] gpio: Langwell GPIO driver miscellaneous clean-ups

[Alek Du]

On Wed, 25 Nov 2009 04:29:37 +0800
Andrew Morton <akpm@linux-foundation.org> wrote:

> On Sun, 22 Nov 2009 11:19:01 +0800
> Alek Du <alek.du@intel.com> wrote:
> 
> > >From 9ba8224f5246ef7fdf1c0a15bb5535e442731435 Mon Sep 17 00:00:00 2001
> > From: Alek Du <alek.du@intel.com>
> > Date: Sun, 22 Nov 2009 10:58:21 +0800
> > Subject: [PATCH] gpio: Langwell GPIO driver miscellaneous clean-ups
> > 
> > 1. Use >= N to check invalid gpio number (unsigned type)
> 
> I already had this in gpio-fix-test-on-unsigned-in-lnw_irq_type.patch
> 
> > 2. Remove wrong and unnecessary unmask operation
> > 3. Remove extra GEDR reading
> > 
> > The 2) and 3) will fix interrupts losing when two or more pins are triggered at close time.
> > 
> 
> Those aren't cleanups - they're bug fixes!
I agree, thx.

> 
> How important are they?

It is not show stopper one, but would be great if could commit to 2.6.32 rcx.

Thanks,
Alek