[alsa-devel] [PATCH] ASoC: fsl_dma: Pass the proper device for dma mapping routines

[Grant Likely]

On Sun, Apr 5, 2009 at 2:52 AM, Anton Vorontsov
<avorontsov at ru.mvista.com> wrote:
> On Sat, Apr 04, 2009 at 11:59:39PM -0600, Grant Likely wrote:
>> Becky & Kumar,
>>
>> Considering these fixups, would it be advisable for the dma functions
>> to climb up the dev->parent linkage when dma_ops are NULL?
>
> pcm->dev->parent doesn't point to the proper device, so
> this won't work.

What does it point to then?  IIUC, following the ->parent links should
eventually get to a struct device that represents the platform or
of_platform device for purposes of power management.

BTW, I'm not NAKing your patch.  The patch looks fine to me.

g.

>
>> On Sat, Apr 4, 2009 at 12:33 PM, Anton Vorontsov
>> <avorontsov at ru.mvista.com> wrote:
>> > The driver should pass a device that specifies internal DMA ops, but
>> > substream->pcm is just a logical device, and thus doesn't have arch-
>> > specific dma callbacks, therefore following bug appears:
>> >
>> >  Freescale Synchronous Serial Interface (SSI) ASoC Driver
>> >  ------------[ cut here ]------------
>> >  kernel BUG at arch/powerpc/include/asm/dma-mapping.h:237!
>> >  Oops: Exception in kernel mode, sig: 5 [#1]
>> >  ...
>> >  NIP [c02259c4] snd_malloc_dev_pages+0x58/0xac
>> >  LR [c0225c74] snd_dma_alloc_pages+0xf8/0x108
>> >  Call Trace:
>> >  [df02bde0] [df02be2c] 0xdf02be2c (unreliable)
>> >  [df02bdf0] [c0225c74] snd_dma_alloc_pages+0xf8/0x108
>> >  [df02be10] [c023a100] fsl_dma_new+0x68/0x124
>> >  [df02be20] [c02342ac] soc_new_pcm+0x1bc/0x234
>> >  [df02bea0] [c02343dc] snd_soc_new_pcms+0xb8/0x148
>> >  [df02bed0] [c023824c] cs4270_probe+0x34/0x124
>> >  [df02bef0] [c0232fe8] snd_soc_instantiate_card+0x1a4/0x2f4
>> >  [df02bf20] [c0233164] snd_soc_instantiate_cards+0x2c/0x68
>> >  [df02bf30] [c0234704] snd_soc_register_platform+0x60/0x80
>> >  [df02bf50] [c03d5664] fsl_soc_platform_init+0x18/0x28
>> >  ...
>> >
>> > This patch fixes the issue by using card's device instead.
>> >
>> > Signed-off-by: Anton Vorontsov <avorontsov at ru.mvista.com>
>> > ---
>> >  sound/soc/fsl/fsl_dma.c |   12 ++++++------
>> >  1 files changed, 6 insertions(+), 6 deletions(-)
>> >
>> > diff --git a/sound/soc/fsl/fsl_dma.c b/sound/soc/fsl/fsl_dma.c
>> > index b3eb857..835e43c 100644
>> > --- a/sound/soc/fsl/fsl_dma.c
>> > +++ b/sound/soc/fsl/fsl_dma.c
>> > @@ -300,7 +300,7 @@ static int fsl_dma_new(struct snd_card *card, struct snd_soc_dai *dai,
>> >        if (!card->dev->coherent_dma_mask)
>> >                card->dev->coherent_dma_mask = fsl_dma_dmamask;
>> >
>> > -       ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->dev,
>> > +       ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, card->dev,
>> >                fsl_dma_hardware.buffer_bytes_max,
>> >                &pcm->streams[0].substream->dma_buffer);
>> >        if (ret) {
>> > @@ -310,7 +310,7 @@ static int fsl_dma_new(struct snd_card *card, struct snd_soc_dai *dai,
>> >                return -ENOMEM;
>> >        }
>> >
>> > -       ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, pcm->dev,
>> > +       ret = snd_dma_alloc_pages(SNDRV_DMA_TYPE_DEV, card->dev,
>> >                fsl_dma_hardware.buffer_bytes_max,
>> >                &pcm->streams[1].substream->dma_buffer);
>> >        if (ret) {
>> > @@ -418,7 +418,7 @@ static int fsl_dma_open(struct snd_pcm_substream *substream)
>> >                return -EBUSY;
>> >        }
>> >
>> > -       dma_private = dma_alloc_coherent(substream->pcm->dev,
>> > +       dma_private = dma_alloc_coherent(substream->pcm->card->dev,
>> >                sizeof(struct fsl_dma_private), &ld_buf_phys, GFP_KERNEL);
>> >        if (!dma_private) {
>> >                dev_err(substream->pcm->card->dev,
>> > @@ -445,7 +445,7 @@ static int fsl_dma_open(struct snd_pcm_substream *substream)
>> >                dev_err(substream->pcm->card->dev,
>> >                        "can't register ISR for IRQ %u (ret=%i)\n",
>> >                        dma_private->irq, ret);
>> > -               dma_free_coherent(substream->pcm->dev,
>> > +               dma_free_coherent(substream->pcm->card->dev,
>> >                        sizeof(struct fsl_dma_private),
>> >                        dma_private, dma_private->ld_buf_phys);
>> >                return ret;
>> > @@ -761,13 +761,13 @@ static int fsl_dma_close(struct snd_pcm_substream *substream)
>> >                        free_irq(dma_private->irq, dma_private);
>> >
>> >                if (dma_private->ld_buf_phys) {
>> > -                       dma_unmap_single(substream->pcm->dev,
>> > +                       dma_unmap_single(substream->pcm->card->dev,
>> >                                dma_private->ld_buf_phys,
>> >                                sizeof(dma_private->link), DMA_TO_DEVICE);
>> >                }
>> >
>> >                /* Deallocate the fsl_dma_private structure */
>> > -               dma_free_coherent(substream->pcm->dev,
>> > +               dma_free_coherent(substream->pcm->card->dev,
>> >                        sizeof(struct fsl_dma_private),
>> >                        dma_private, dma_private->ld_buf_phys);
>> >                substream->runtime->private_data = NULL;
>> > --
>> > 1.5.6.5
>> > _______________________________________________
>> > Linuxppc-dev mailing list
>> > Linuxppc-dev at ozlabs.org
>> > https://ozlabs.org/mailman/listinfo/linuxppc-dev
>> >
>>
>>
>>
>> --
>> Grant Likely, B.Sc., P.Eng.
>> Secret Lab Technologies Ltd.
>
> --
> Anton Vorontsov
> email: cbouatmailru at gmail.com
> irc://irc.freenode.net/bd2
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.