[alsa-devel] [PATCH v3] dbri: Fix compiler warning

[Takashi Iwai]

On Fri, 25 Nov 2016 17:54:47 +0100,
David Miller wrote:
> 
> From: Takashi Iwai <tiwai at suse.de>
> Date: Fri, 25 Nov 2016 10:30:48 +0100
> 
> > On Thu, 24 Nov 2016 21:35:16 +0100,
> > Tushar Dave wrote:
> >> 
> >> dbri uses 'u32' for dma handle while invoking kernel DMA APIs,
> >> instead of using dma_addr_t. This hasn't caused any 'incompatible
> >> pointer type' warning on SPARC because until now dma_addr_t is of
> >> type u32. However, recent changes in SPARC ATU (iommu) enabled 64bit
> >> DMA and therefore dma_addr_t became of type u64. This makes
> >> 'incompatible pointer type' warnings inevitable.
> >> 
> >> e.g.
> >> sound/sparc/dbri.c: In function ‘snd_dbri_create’:
> >> sound/sparc/dbri.c:2538: warning: passing argument 3 of ‘dma_zalloc_coherent’ from incompatible pointer type
> >> ./include/linux/dma-mapping.h:608: note: expected ‘dma_addr_t *’ but argument is of type ‘u32 *’
> >> 
> >> For the record, dbri(sbus) driver never executes on sun4v. Therefore
> >> even though 64bit DMA is enabled on SPARC, dbri continues to use
> >> legacy iommu that guarantees DMA address is always in 32bit range.
> >> 
> >> This patch resolves above compiler warning.
> >> 
> >> Signed-off-by: Tushar Dave <tushar.n.dave at oracle.com>
> >> Reviewed-by: thomas tai <thomas.tai at oracle.com>
> >> ---
> >> v2->v3:
> >> - Use %pad to print dma_addr_t. Comment by Takashi Iwai.
> > 
> > Applied now.  Thanks!
> 
> This patch is absolutely not appropriate for your tree Takashi.
> 
> It's for the sparc tree because that's where the dma_addr_t
> type was changed from 32-bit to 64-bit on sparc64, which is
> what caused this build warning.
> 
> Dave, please only send sparc specific driver patches to
> sparclinux at vger.kernel.org in the future so we can avoid
> this kind of problem.  The whole handling of the dma_addr_t
> type change on sparc64 has been a real mess, quite honestly.

Fair enough.  Could you take it through your tree?
Feel free to take my ack:
  Reviewed-by: Takashi Iwai <tiwai at suse.de>


Thanks!

Takashi