[PATCH V2] net: stmmac: use msleep instead of udelay for gpio reset

[PATCH V2] net: stmmac: use msleep instead of udelay for gpio reset

[Michael Trimarchi]

Reset delay values are expressed in microsecond but most of the
time the delay is more then 2ms and up to 100ms. Use udelay
is wrong for large sleep period. This function is not used
in interrupt context according to the documentation.

Cc: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>

---
Changes v1 -> v2:
  - remove unreleated changes
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
index b735fa2..c843fbe 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c
@@ -161,11 +161,11 @@ int stmmac_mdio_reset(struct mii_bus *bus)
 
 		if (!gpio_request(reset_gpio, "mdio-reset")) {
 			gpio_direction_output(reset_gpio, active_low ? 1 : 0);
-			udelay(data->delays[0]);
-			gpio_set_value(reset_gpio, active_low ? 0 : 1);
-			udelay(data->delays[1]);
-			gpio_set_value(reset_gpio, active_low ? 1 : 0);
-			udelay(data->delays[2]);
+			msleep(max(1U, data->delays[0] / 1000));
+			gpio_set_value(reset_gpio, !active_low);
+			msleep(max(1U, data->delays[1] / 1000));
+			gpio_set_value(reset_gpio, active_low);
+			msleep(max(1U, data->delays[2] / 1000));
 		}
 	}
 #endif
-- 
1.9.1

Re: [PATCH V2] net: stmmac: use msleep instead of udelay for gpio reset

[David Miller]

From: Michael Trimarchi <michael@amarulasolutions.com>
Date: Tue, 21 Apr 2015 13:16:13 +0200

> -			udelay(data->delays[0]);
 ...
> +			msleep(max(1U, data->delays[0] / 1000));

That looks very ugly with that max() expression in there.

Please find some clean way to get rid of it if you want to
make this conversion.

Thanks.

Re: [PATCH V2] net: stmmac: use msleep instead of udelay for gpio reset

[Michael Trimarchi]

Hi

On Tue, Apr 21, 2015 at 05:35:40PM -0400, David Miller wrote:
> From: Michael Trimarchi <michael@amarulasolutions.com>
> Date: Tue, 21 Apr 2015 13:16:13 +0200
> 
> > -			udelay(data->delays[0]);
>  ...
> > +			msleep(max(1U, data->delays[0] / 1000));
> 
> That looks very ugly with that max() expression in there.
>

Is fine for you a DIV_ROUND_UP?

> Please find some clean way to get rid of it if you want to
> make this conversion.
>

Agree, I will repost it

Michael

> Thanks.

-- 
| Michael Nazzareno Trimarchi                     Amarula Solutions BV |
| COO  -  Founder                                      Cruquiuskade 47 |
| +31(0)851119172                                 Amsterdam 1018 AM NL |
|                  [`as] http://www.amarulasolutions.com               |

Re: [PATCH V2] net: stmmac: use msleep instead of udelay for gpio reset

[David Miller]

From: Michael Trimarchi <michael@amarulasolutions.com>
Date: Wed, 22 Apr 2015 01:13:47 +0200

> Hi
> 
> On Tue, Apr 21, 2015 at 05:35:40PM -0400, David Miller wrote:
>> From: Michael Trimarchi <michael@amarulasolutions.com>
>> Date: Tue, 21 Apr 2015 13:16:13 +0200
>> 
>> > -			udelay(data->delays[0]);
>>  ...
>> > +			msleep(max(1U, data->delays[0] / 1000));
>> 
>> That looks very ugly with that max() expression in there.
>>
> 
> Is fine for you a DIV_ROUND_UP?

Not inside of these simple msleep() calls, no.

How about adjusting the values either in the datastructure or
in local variables instead?  That wasn't so hard to come up
with now, was it?

Re: [PATCH V2] net: stmmac: use msleep instead of udelay for gpio reset

[Michael Trimarchi]

Hi

On Tue, Apr 21, 2015 at 08:31:34PM -0400, David Miller wrote:
> From: Michael Trimarchi <michael@amarulasolutions.com>
> Date: Wed, 22 Apr 2015 01:13:47 +0200
> 
> > Hi
> > 
> > On Tue, Apr 21, 2015 at 05:35:40PM -0400, David Miller wrote:
> >> From: Michael Trimarchi <michael@amarulasolutions.com>
> >> Date: Tue, 21 Apr 2015 13:16:13 +0200
> >> 
> >> > -			udelay(data->delays[0]);
> >>  ...
> >> > +			msleep(max(1U, data->delays[0] / 1000));
> >> 
> >> That looks very ugly with that max() expression in there.
> >>
> > 
> > Is fine for you a DIV_ROUND_UP?
> 
> Not inside of these simple msleep() calls, no.
> 
> How about adjusting the values either in the datastructure or
> in local variables instead?  That wasn't so hard to come up
> with now, was it?

Ok, it's easy no problem at all, I will post later today but I prefer
local variables and use DIV_ROUND_UP

Michael