Re: [PATCH v2] net: mvmdio: fix interrupt timeout handling

From: Jason Gunthorpe
Date: Thu Dec 19 2013 - 12:43:55 EST


On Thu, Dec 19, 2013 at 01:09:48PM +0000, Leigh Brown wrote:
> This version corrects the whitespace issue.
>
> orion_mdio_wait_ready uses wait_event_timeout to wait for the
> SMI interrupt to fire. wait_event_timeout waits for between
> "timeout - 1" and "timeout" jiffies. In this case a 1ms timeout
> when HZ is 1000 results in a wait of 0 to 1 jiffies, causing
> premature timeouts.
>
> This fix ensures a minimum timeout of 2 jiffies, ensuring
> wait_event_timeout will always wait at least 1 jiffie.
>
> Issue reported by Nicolas Schichan.
>
> Tested-by: Nicolas Schichan <nschichan@xxxxxxxxxx>
> Signed-off-by: Leigh Brown <leigh@xxxxxxxxxxxxx>
> drivers/net/ethernet/marvell/mvmdio.c | 6 ++++++
> 1 file changed, 6 insertions(+)

Leigh, I have just noticed a regression in 3.13-rc3 vs 3.10, on
kirkwood where 3.13 occasionally prints:

3 12/11 13:59:02 kernel: orion-mdio f1072004.mdio: Timeout: SMI busy for too long

Is that the same issue that this patch is addressing?

Regards,
Jason
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