[PATCH] mtd: nand: pxa3xx: Switch FIFO draining to jiffies-based timeout

[PATCH] mtd: nand: pxa3xx: Switch FIFO draining to jiffies-based timeout

[Maxime Ripard]

Now that the driver handles the FIFO draining in a threaded interrupt, we can
base our timeout on jiffies and sleeping, instead of using mdelay.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/mtd/nand/pxa3xx_nand.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
index 3f09f2e9aeb4..1eb957c347cd 100644
--- a/drivers/mtd/nand/pxa3xx_nand.c
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -496,16 +496,15 @@ static void drain_fifo(struct pxa3xx_nand_info *info, void *data, int len)
 		while (len > 8) {
 			__raw_readsl(info->mmio_base + NDDB, data, 8);
 
-			for (timeout = 0;
-			     !(nand_readl(info, NDSR) & NDSR_RDDREQ);
-			     timeout++) {
-				if (timeout >= 5) {
+			timeout = jiffies + msecs_to_jiffies(5);
+			while (!(nand_readl(info, NDSR) & NDSR_RDDREQ)) {
+				if (!time_before(jiffies, timeout)) {
 					dev_err(&info->pdev->dev,
 						"Timeout on RDDREQ while draining the FIFO\n");
 					return;
 				}
 
-				mdelay(1);
+				msleep(1);
 			}
 
 			data += 32;
-- 
2.3.0

[PATCH] mtd: nand: pxa3xx: Switch FIFO draining to jiffies-based timeout

[Baruch Siach]

Hi Maxime,

On Tue, Mar 03, 2015 at 10:55:29AM +0100, Maxime Ripard wrote:
> Now that the driver handles the FIFO draining in a threaded interrupt, we can
> base our timeout on jiffies and sleeping, instead of using mdelay.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/mtd/nand/pxa3xx_nand.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
> index 3f09f2e9aeb4..1eb957c347cd 100644
> --- a/drivers/mtd/nand/pxa3xx_nand.c
> +++ b/drivers/mtd/nand/pxa3xx_nand.c
> @@ -496,16 +496,15 @@ static void drain_fifo(struct pxa3xx_nand_info *info, void *data, int len)
>  		while (len > 8) {
>  			__raw_readsl(info->mmio_base + NDDB, data, 8);
>  
> -			for (timeout = 0;
> -			     !(nand_readl(info, NDSR) & NDSR_RDDREQ);
> -			     timeout++) {
> -				if (timeout >= 5) {
> +			timeout = jiffies + msecs_to_jiffies(5);
> +			while (!(nand_readl(info, NDSR) & NDSR_RDDREQ)) {
> +				if (!time_before(jiffies, timeout)) {
>  					dev_err(&info->pdev->dev,
>  						"Timeout on RDDREQ while draining the FIFO\n");
>  					return;
>  				}
>  
> -				mdelay(1);
> +				msleep(1);
>  			}

You may want to consider using readl_relaxed_poll_timeout() from 
linux/iopoll.h, which was introduced in v4.0-rc1.

baruch

-- 
     http://baruch.siach.name/blog/                  ~. .~   Tk Open Systems
=}------------------------------------------------ooO--U--Ooo------------{=
   - baruch at tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -

[PATCH] mtd: nand: pxa3xx: Switch FIFO draining to jiffies-based timeout

[maxime.ripard at free-electrons.com]

Hi Baruch,

On Tue, Mar 03, 2015 at 12:18:46PM +0200, Baruch Siach wrote:
> Hi Maxime,
> 
> On Tue, Mar 03, 2015 at 10:55:29AM +0100, Maxime Ripard wrote:
> > Now that the driver handles the FIFO draining in a threaded interrupt, we can
> > base our timeout on jiffies and sleeping, instead of using mdelay.
> > 
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >  drivers/mtd/nand/pxa3xx_nand.c | 9 ++++-----
> >  1 file changed, 4 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
> > index 3f09f2e9aeb4..1eb957c347cd 100644
> > --- a/drivers/mtd/nand/pxa3xx_nand.c
> > +++ b/drivers/mtd/nand/pxa3xx_nand.c
> > @@ -496,16 +496,15 @@ static void drain_fifo(struct pxa3xx_nand_info *info, void *data, int len)
> >  		while (len > 8) {
> >  			__raw_readsl(info->mmio_base + NDDB, data, 8);
> >  
> > -			for (timeout = 0;
> > -			     !(nand_readl(info, NDSR) & NDSR_RDDREQ);
> > -			     timeout++) {
> > -				if (timeout >= 5) {
> > +			timeout = jiffies + msecs_to_jiffies(5);
> > +			while (!(nand_readl(info, NDSR) & NDSR_RDDREQ)) {
> > +				if (!time_before(jiffies, timeout)) {
> >  					dev_err(&info->pdev->dev,
> >  						"Timeout on RDDREQ while draining the FIFO\n");
> >  					return;
> >  				}
> >  
> > -				mdelay(1);
> > +				msleep(1);
> >  			}
> 
> You may want to consider using readl_relaxed_poll_timeout() from 
> linux/iopoll.h, which was introduced in v4.0-rc1.

Thanks for pointing this out.

I'll send a new version using this.

Thanks!
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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