Messages in this thread | | | Date | Wed, 31 Oct 2012 10:59:24 +0100 | From | Nicolas Ferre <> | Subject | Re: [PATCH v3 06/10] net/macb: clean up ring buffer logic |
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On 10/30/2012 07:22 PM, Håvard Skinnemoen : > On Tue, Oct 30, 2012 at 4:12 AM, David Laight <David.Laight@aculab.com> wrote: >>> Instead of masking head and tail every time we increment them, just let them >>> wrap through UINT_MAX and mask them when subscripting. Add simple accessor >>> functions to do the subscripting properly to minimize the chances of messing >>> this up. >> ... >>> +static unsigned int macb_tx_ring_avail(struct macb *bp) >>> +{ >>> + return TX_RING_SIZE - (bp->tx_head - bp->tx_tail); >>> +} >> >> That one doesn't look quite right to me. >> Surely it should be masking with 'TX_RING_SIZE - 1' > > Why is that? head and tail can never be more than TX_RING_SIZE apart, > so it shouldn't make any difference.
Absolutely.
Best regards, -- Nicolas Ferre -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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