Andrew Morton wrote:
>
> On Mon, 3 Oct 2011 10:53:45 -0700
> "Bounine, Alexandre" <alexandre.boun...@idt.com> wrote:
>
> > > > + memset(bd_ptr, 0, bd_num * sizeof(struct
tsi721_dma_desc));
> > > > +
> > > > + dev_dbg(dev, "DMA descriptors @ %p (phys = %llx)\n",
> > > > + bd_ptr, (unsigned long long)bd_phys);
> > > > +
> > > > + /* Allocate space for descriptor status FIFO */
> > > > + sts_size = (bd_num >= TSI721_DMA_MINSTSSZ) ?
> > > > + bd_num :
TSI721_DMA_MINSTSSZ;
> > > > + sts_size = roundup_pow_of_two(sts_size);
> > > > + sts_ptr = dma_alloc_coherent(dev,
> > > > + sts_size * sizeof(struct
> > tsi721_dma_sts),
> > > > + &sts_phys, GFP_KERNEL);
> > > > + if (!sts_ptr) {
> > > > + /* Free space allocated for DMA descriptors */
> > > > + dma_free_coherent(dev,
> > > > + bd_num * sizeof(struct
> > tsi721_dma_desc),
> > > > + bd_ptr, bd_phys);
> > > > + chan->bd_base = NULL;
> > > > + return -ENOMEM;
> > > > + }
> > > > +
> > > > + chan->sts_phys = sts_phys;
> > > > + chan->sts_base = sts_ptr;
> > > > + chan->sts_size = sts_size;
> > > > +
> > > > + memset(sts_ptr, 0, sts_size);
> > >
> > > You meant
> >
> > I really need it here. That status block tracks progress by keeping
> > non-zero addresses of processed descriptors.
>
> Confused. Are you saying that the use of "sts_size" there was
> intentional?
Sorry, somehow I mistakenly linked this comment to dma_zalloc_coherent()
because of use of memset.
Yes, it should be "sts_size * sizeof(struct tsi721_dma_sts)" as
allocated.
> > >
> > > --- a/drivers/rapidio/devices/tsi721.c~rapidio-tsi721-add-dma-
> engine-
> > > support-fix
> > > +++ a/drivers/rapidio/devices/tsi721.c
> > > @@ -1006,7 +1006,7 @@ static int tsi721_bdma_maint_init(struct
> > > priv->mdma.sts_base = sts_ptr;
> > > priv->mdma.sts_size = sts_size;
> > >
> > > - memset(sts_ptr, 0, sts_size);
> > > + memset(sts_ptr, 0, sts_size * sizeof(struct tsi721_dma_sts));
> > >
> > > dev_dbg(&priv->pdev->dev,
> > > "desc status FIFO @ %p (phys = %llx) size=0x%x\n",
> > >
> > > However that's at least two instances where you wanted a
> > > dma_zalloc_coherent(). How's about we give ourselves one?
> >
> > Does this mean that I am on hook for it as a "most frequent user"?
>
> No, it can be used all over the place: drivers/net/irda/w83977af_ir.c,
> drivers/scsi/bnx2fc/bnx2fc_tgt.c,
> drivers/net/wireless/rt2x00/rt2x00pci.c,
> drivers/crypto/amcc/crypto4xx_core.c and many nmore.
In this case I will happily use dma_zalloc_coherent() as soon as
it is available
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