[PATCH v2 27/27] sound: ppc: remove unneeded memset after dma_alloc_coherent

[PATCH v2 27/27] sound: ppc: remove unneeded memset after dma_alloc_coherent

[Fuqian Huang]

In commit af7ddd8a627c
("Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping"),
dma_alloc_coherent has already zeroed the memory.
So memset is not needed.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
---
 sound/ppc/pmac.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/sound/ppc/pmac.c b/sound/ppc/pmac.c
index 1b11e53f6a62..1ab12f4f8631 100644
--- a/sound/ppc/pmac.c
+++ b/sound/ppc/pmac.c
@@ -56,7 +56,6 @@ static int snd_pmac_dbdma_alloc(struct snd_pmac *chip, struct pmac_dbdma *rec, i
 	if (rec->space == NULL)
 		return -ENOMEM;
 	rec->size = size;
-	memset(rec->space, 0, rsize);
 	rec->cmds = (void __iomem *)DBDMA_ALIGN(rec->space);
 	rec->addr = rec->dma_base + (unsigned long)((char *)rec->cmds - (char *)rec->space);
 
-- 
2.11.0

Re: [PATCH v2 27/27] sound: ppc: remove unneeded memset after dma_alloc_coherent

[Christophe Leroy]

Le 28/06/2019 à 04:50, Fuqian Huang a écrit :
> In commit af7ddd8a627c
> ("Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping"),
> dma_alloc_coherent has already zeroed the memory.
> So memset is not needed.

You are refering to a merge commit, is that correct ?

I can't see anything related in that commit, can you please pinpoint it ?

As far as I can see, on powerpc the memory has always been zeroized 
(since 2005 at least).

Christophe

> 
> Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
> ---
>   sound/ppc/pmac.c | 1 -
>   1 file changed, 1 deletion(-)
> 
> diff --git a/sound/ppc/pmac.c b/sound/ppc/pmac.c
> index 1b11e53f6a62..1ab12f4f8631 100644
> --- a/sound/ppc/pmac.c
> +++ b/sound/ppc/pmac.c
> @@ -56,7 +56,6 @@ static int snd_pmac_dbdma_alloc(struct snd_pmac *chip, struct pmac_dbdma *rec, i
>   	if (rec->space == NULL)
>   		return -ENOMEM;
>   	rec->size = size;
> -	memset(rec->space, 0, rsize);
>   	rec->cmds = (void __iomem *)DBDMA_ALIGN(rec->space);
>   	rec->addr = rec->dma_base + (unsigned long)((char *)rec->cmds - (char *)rec->space);
>   
> 

Re: [PATCH v2 27/27] sound: ppc: remove unneeded memset after dma_alloc_coherent

[Fuqian Huang]

The merge commit log tells (dma-mapping: zero memory returned from
dma_alloc_* and deprecating the dma_zalloc_coherent).
I used this commit just want to say that dma_alloc_coherent  has
zeroed the allocated memory.
Sorry for this mistake.

Maybe this commit 518a2f1925c3("dma-mapping: zero memory returned from
dma_alloc_*") is correct.

Christophe Leroy <christophe.leroy@c-s.fr> 於 2019年6月28日週五 下午4:59寫道：

>
>
>
> Le 28/06/2019 à 04:50, Fuqian Huang a écrit :
> > In commit af7ddd8a627c
> > ("Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping"),
> > dma_alloc_coherent has already zeroed the memory.
> > So memset is not needed.
>
> You are refering to a merge commit, is that correct ?
>
> I can't see anything related in that commit, can you please pinpoint it ?
>
> As far as I can see, on powerpc the memory has always been zeroized
> (since 2005 at least).
>
> Christophe
>
> >
> > Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
> > ---
> >   sound/ppc/pmac.c | 1 -
> >   1 file changed, 1 deletion(-)
> >
> > diff --git a/sound/ppc/pmac.c b/sound/ppc/pmac.c
> > index 1b11e53f6a62..1ab12f4f8631 100644
> > --- a/sound/ppc/pmac.c
> > +++ b/sound/ppc/pmac.c
> > @@ -56,7 +56,6 @@ static int snd_pmac_dbdma_alloc(struct snd_pmac *chip, struct pmac_dbdma *rec, i
> >       if (rec->space == NULL)
> >               return -ENOMEM;
> >       rec->size = size;
> > -     memset(rec->space, 0, rsize);
> >       rec->cmds = (void __iomem *)DBDMA_ALIGN(rec->space);
> >       rec->addr = rec->dma_base + (unsigned long)((char *)rec->cmds - (char *)rec->space);
> >
> >

Re: [alsa-devel] [PATCH v2 27/27] sound: ppc: remove unneeded memset after dma_alloc_coherent

[Takashi Iwai]

On Fri, 28 Jun 2019 11:11:08 +0200,
Fuqian Huang wrote:
> 
> The merge commit log tells (dma-mapping: zero memory returned from
> dma_alloc_* and deprecating the dma_zalloc_coherent).
> I used this commit just want to say that dma_alloc_coherent  has
> zeroed the allocated memory.
> Sorry for this mistake.
> 
> Maybe this commit 518a2f1925c3("dma-mapping: zero memory returned from
> dma_alloc_*") is correct.

Are you going to resubmit v3 patchset?  If the correction is specific
to this patch, I can correct the description in my side, too...


thanks,

Takashi

> 
> Christophe Leroy <christophe.leroy@c-s.fr> 於 2019年6月28日週五 下午4:59寫道：
> 
> >
> >
> >
> > Le 28/06/2019 à 04:50, Fuqian Huang a écrit :
> > > In commit af7ddd8a627c
> > > ("Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping"),
> > > dma_alloc_coherent has already zeroed the memory.
> > > So memset is not needed.
> >
> > You are refering to a merge commit, is that correct ?
> >
> > I can't see anything related in that commit, can you please pinpoint it ?
> >
> > As far as I can see, on powerpc the memory has always been zeroized
> > (since 2005 at least).
> >
> > Christophe
> >
> > >
> > > Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
> > > ---
> > >   sound/ppc/pmac.c | 1 -
> > >   1 file changed, 1 deletion(-)
> > >
> > > diff --git a/sound/ppc/pmac.c b/sound/ppc/pmac.c
> > > index 1b11e53f6a62..1ab12f4f8631 100644
> > > --- a/sound/ppc/pmac.c
> > > +++ b/sound/ppc/pmac.c
> > > @@ -56,7 +56,6 @@ static int snd_pmac_dbdma_alloc(struct snd_pmac *chip, struct pmac_dbdma *rec, i
> > >       if (rec->space == NULL)
> > >               return -ENOMEM;
> > >       rec->size = size;
> > > -     memset(rec->space, 0, rsize);
> > >       rec->cmds = (void __iomem *)DBDMA_ALIGN(rec->space);
> > >       rec->addr = rec->dma_base + (unsigned long)((char *)rec->cmds - (char *)rec->space);
> > >
> > >
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> https://mailman.alsa-project.org/mailman/listinfo/alsa-devel

Re: [PATCH v2 27/27] sound: ppc: remove unneeded memset after dma_alloc_coherent

[Christophe Leroy]

Le 28/06/2019 à 11:11, Fuqian Huang a écrit :
> The merge commit log tells (dma-mapping: zero memory returned from
> dma_alloc_* and deprecating the dma_zalloc_coherent).
> I used this commit just want to say that dma_alloc_coherent  has
> zeroed the allocated memory.
> Sorry for this mistake.
> 
> Maybe this commit 518a2f1925c3("dma-mapping: zero memory returned from
> dma_alloc_*") is correct.

Yes that looks appropriate. And it confirms it was already done on 
powerpc, as that patch doesn't include any change in powerpc arch.

Christophe

> 
> Christophe Leroy <christophe.leroy@c-s.fr> 於 2019年6月28日週五 下午4:59寫道：
> 
>>
>>
>>
>> Le 28/06/2019 à 04:50, Fuqian Huang a écrit :
>>> In commit af7ddd8a627c
>>> ("Merge tag 'dma-mapping-4.21' of git://git.infradead.org/users/hch/dma-mapping"),
>>> dma_alloc_coherent has already zeroed the memory.
>>> So memset is not needed.
>>
>> You are refering to a merge commit, is that correct ?
>>
>> I can't see anything related in that commit, can you please pinpoint it ?
>>
>> As far as I can see, on powerpc the memory has always been zeroized
>> (since 2005 at least).
>>
>> Christophe
>>
>>>
>>> Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
>>> ---
>>>    sound/ppc/pmac.c | 1 -
>>>    1 file changed, 1 deletion(-)
>>>
>>> diff --git a/sound/ppc/pmac.c b/sound/ppc/pmac.c
>>> index 1b11e53f6a62..1ab12f4f8631 100644
>>> --- a/sound/ppc/pmac.c
>>> +++ b/sound/ppc/pmac.c
>>> @@ -56,7 +56,6 @@ static int snd_pmac_dbdma_alloc(struct snd_pmac *chip, struct pmac_dbdma *rec, i
>>>        if (rec->space == NULL)
>>>                return -ENOMEM;
>>>        rec->size = size;
>>> -     memset(rec->space, 0, rsize);
>>>        rec->cmds = (void __iomem *)DBDMA_ALIGN(rec->space);
>>>        rec->addr = rec->dma_base + (unsigned long)((char *)rec->cmds - (char *)rec->space);
>>>
>>>