Re: [PATCH] igb: fix PHC stopping on max freq

[Jeff Kirsher <jeffrey.t.kirsher@intel.com>]

[-- Attachment #1: Type: text/plain, Size: 885 bytes --]

On Tue, 2013-03-19 at 15:42 +0100, Jiri Benc wrote:
> For 82576 MAC type, max_adj is reported as 1000000000 ppb. However, if
> this value is passed to igb_ptp_adjfreq_82576, incvalue overflows out
> of
> INCVALUE_82576_MASK, resulting in setting of zero TIMINCA.incvalue,
> stopping
> the PHC (instead of going at twice the nominal speed).
> 
> Fix the advertised max_adj value to the largest value hardware can
> handle.
> As there is no min_adj value available (-max_adj is used instead),
> this will
> also prevent stopping the clock intentionally. It's probably not a big
> deal,
> other igb MAC types don't support stopping the clock, either.
> 
> Signed-off-by: Jiri Benc <jbenc@redhat.com>
> ---
>  drivers/net/ethernet/intel/igb/igb_ptp.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-) 

Thanks Jiri, I have added the patch to my igb queue

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 836 bytes --]