RE: [PATCH v2 1/4] drivers/net/b44: Change to non-atomic bit operations

From: David Laight
Date: Tue Nov 26 2019 - 04:49:14 EST


From: Fenghua Yu
> Sent: 25 November 2019 19:43
> From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
>
> Since "pwol_mask" is local and never exposed to concurrency, there is
> no need to set bit in pwol_mask by costly atomic operations.
>
> Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx>
> ---
> drivers/net/ethernet/broadcom/b44.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/broadcom/b44.c b/drivers/net/ethernet/broadcom/b44.c
> index 97ab0dd25552..5738ab963dfb 100644
> --- a/drivers/net/ethernet/broadcom/b44.c
> +++ b/drivers/net/ethernet/broadcom/b44.c
> @@ -1520,7 +1520,7 @@ static int b44_magic_pattern(u8 *macaddr, u8 *ppattern, u8 *pmask, int offset)
>
> memset(ppattern + offset, 0xff, magicsync);
> for (j = 0; j < magicsync; j++)
> - set_bit(len++, (unsigned long *) pmask);
> + __set_bit(len++, (unsigned long *)pmask);

While this stops the misaligned locks, the code is still horribly borked on BE systems.
The way pmask is used definitely wanst a u32[] not a u64[] one.

David

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