From: Andrew Morton <akpm00@gmail.com>
To: "Bounine, Alexandre" <Alexandre.Bounine@idt.com>
Cc: Vinod Koul <vinod.koul@intel.com>,
linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Subject: Re: [RFC PATCH 2/2 -mm] RapidIO: TSI721 Add DMA Engine support
Date: Tue, 4 Oct 2011 14:43:53 -0700 [thread overview]
Message-ID: <20111004144353.18087914.akpm00@gmail.com> (raw)
In-Reply-To: <0CE8B6BE3C4AD74AB97D9D29BD24E55202291E8D@CORPEXCH1.na.ads.idt.com>
On Mon, 3 Oct 2011 10:53:45 -0700
"Bounine, Alexandre" <Alexandre.Bounine@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?
> >
> > --- 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.
next prev parent reply other threads:[~2011-10-04 21:44 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-30 21:38 [RFC PATCH 1/2] RapidIO: Add DMA Engine support for RIO data transfers Alexandre Bounine
2011-09-30 21:38 ` [RFC PATCH 2/2 -mm] RapidIO: TSI721 Add DMA Engine support Alexandre Bounine
2011-09-30 22:15 ` Andrew Morton
2011-10-03 17:53 ` Bounine, Alexandre
2011-10-04 21:43 ` Andrew Morton [this message]
2011-10-05 1:38 ` Bounine, Alexandre
2011-10-05 1:57 ` Andrew Morton
2011-10-05 2:57 ` Bounine, Alexandre
2011-10-01 18:06 ` Vinod Koul
2011-10-01 18:01 ` [RFC PATCH 1/2] RapidIO: Add DMA Engine support for RIO data transfers Vinod Koul
2011-10-03 16:52 ` Bounine, Alexandre
2011-10-05 20:38 ` Williams, Dan J
2011-10-07 16:12 ` Bounine, Alexandre
2011-10-07 5:27 ` Vinod Koul
2011-10-07 19:08 ` Bounine, Alexandre
2011-10-15 17:35 ` Vinod Koul
2011-10-17 14:33 ` Bounine, Alexandre
2011-10-17 15:52 ` Jassi Brar
2011-10-17 17:01 ` Vinod Koul
2011-10-17 19:39 ` Bounine, Alexandre
2011-10-17 18:16 ` Bounine, Alexandre
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