lkml.org 
[lkml]   [2013]   [Dec]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: Spurious timeouts in mvmdio
On 2013-12-16 18:07, Nicolas Schichan wrote:
> On 12/04/2013 12:42 AM, Russell King - ARM Linux wrote:
>> Alternatively, code it like this instead.
>>
>> drivers/net/ethernet/marvell/mvmdio.c | 32
>> +++++++++++++++-----------------
>> 1 files changed, 15 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/marvell/mvmdio.c
>> b/drivers/net/ethernet/marvell/mvmdio.c
>> index 7354960b583b..a6f59831fc5b 100644
>> --- a/drivers/net/ethernet/marvell/mvmdio.c
>> +++ b/drivers/net/ethernet/marvell/mvmdio.c
>> @@ -76,31 +76,29 @@ static int orion_mdio_wait_ready(struct mii_bus
>> *bus)
>> {
>> struct orion_mdio_dev *dev = bus->priv;
>> unsigned long timeout = usecs_to_jiffies(MVMDIO_SMI_TIMEOUT);
>> - unsigned long end = jiffies + timeout;
>> - int timedout = 0;
>>
>> - while (1) {
>> - if (orion_mdio_smi_is_done(dev))
>> + if (dev->err_interrupt > 0) {
>> + if (wait_event_timeout(dev->smi_busy_wait,
>> + orion_mdio_smi_is_done(dev),
>> + 1 + timeout))
>> return 0;
>> - else if (timedout)
>> - break;
>> + } else {
>> + unsigned long end = jiffies + timeout;
>>
>> - if (dev->err_interrupt <= 0) {
>> - usleep_range(MVMDIO_SMI_POLL_INTERVAL_MIN,
>> - MVMDIO_SMI_POLL_INTERVAL_MAX);
>> + while (1) {
>> + if (orion_mdio_smi_is_done(dev))
>> + return 0;
>>
>> if (time_is_before_jiffies(end))
>> - ++timedout;
>> - } else {
>> - wait_event_timeout(dev->smi_busy_wait,
>> - orion_mdio_smi_is_done(dev),
>> - timeout);
>> -
>> - ++timedout;
>> - }
>> + break;
>> +
>> + usleep_range(MVMDIO_SMI_POLL_INTERVAL_MIN,
>> + MVMDIO_SMI_POLL_INTERVAL_MAX);
>> + }
>> }
>>
>> dev_err(bus->parent, "Timeout: SMI busy for too long\n");
>> +
>> return -ETIMEDOUT;
>> }
>
> Hi Russell,
>
> I did not find any commit for this in 3.13-rc4.
>
> Would you prefer I submit my attempt at refactoring the
> orion_mdio_wait_ready() code ?

I prefer this patch (which I think you originally proposed) because it
is just as
correct and the code size is a bit smaller in arm mode, and the same
size in thumb
mode (on my compiler gcc 4.7.2, at least). I coded the loop in that way
to make it
small.

I don't mind submitting it to David as I made the mistake in the first
place.

Regards,

Leigh.

diff --git a/drivers/net/ethernet/marvell/mvmdio.c
b/drivers/net/ethernet/marvell/mvmdio.c
index 7354960..a42a750 100644
--- a/drivers/net/ethernet/marvell/mvmdio.c
+++ b/drivers/net/ethernet/marvell/mvmdio.c
@@ -92,6 +92,12 @@ static int orion_mdio_wait_ready(struct mii_bus *bus)
if (time_is_before_jiffies(end))
++timedout;
} else {
+ /* wait_event_timeout does not guarantee a delay of at
+ * least one whole jiffie, so timeout must be no less
+ * than two.
+ */
+ if (timeout < 2)
+ timeout = 2;
wait_event_timeout(dev->smi_busy_wait,
orion_mdio_smi_is_done(dev),
timeout);


\
 
 \ /
  Last update: 2013-12-16 20:01    [W:0.091 / U:1.180 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site