dma: axi-dmac: Split too large segments

["Ardelean, Alexandru" <Alex.Ardelean@analog.com>]

On Sat, 2019-02-16 at 17:03 +0800, kbuild test robot wrote:
> 

My bad here.
I took this patch from our kernel tree and sent it.
I assumed it works, since it works in our tree.
I'll take a look and see about the order of patches, and which one(s)
need(s) to be sent before this one

Thanks
Alex

> 
> Hi Lars-Peter,
> 
> I love your patch! Yet something to improve:
> 
> [auto build test ERROR on linus/master]
> [also build test ERROR on v5.0-rc4 next-20190215]
> [if your patch is applied to the wrong git tree, please drop us a note to
> help improve the system]
> 
> url:    
> https://github.com/0day-ci/linux/commits/Alexandru-Ardelean/dma-axi-dmac-Split-too-large-segments/20190216-160002
> config: nds32-allyesconfig (attached as .config)
> compiler: nds32le-linux-gcc (GCC) 6.4.0
> reproduce:
>         wget 
> https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross
> -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         GCC_VERSION=6.4.0 make.cross ARCH=nds32
> 
> All errors (new ones prefixed by >>):
> 
>    drivers//dma/dma-axi-dmac.c: In function 'axi_dmac_prep_slave_sg':
> > > drivers//dma/dma-axi-dmac.c:443:12: error: implicit declaration of
> > > function 'sg_nents_for_dma' [-Werror=implicit-function-declaration]
> 
>      num_sgs = sg_nents_for_dma(sgl, sg_len, chan->max_length);
>                ^~~~~~~~~~~~~~~~
>    cc1: some warnings being treated as errors
> 
> vim +/sg_nents_for_dma +443 drivers//dma/dma-axi-dmac.c
> 
>    427
>    428  static struct dma_async_tx_descriptor *axi_dmac_prep_slave_sg(
>    429          struct dma_chan *c, struct scatterlist *sgl,
>    430          unsigned int sg_len, enum dma_transfer_direction
> direction,
>    431          unsigned long flags, void *context)
>    432  {
>    433          struct axi_dmac_chan *chan = to_axi_dmac_chan(c);
>    434          struct axi_dmac_desc *desc;
>    435          struct axi_dmac_sg *dsg;
>    436          struct scatterlist *sg;
>    437          unsigned int num_sgs;
>    438          unsigned int i;
>    439
>    440          if (direction != chan->direction)
>    441                  return NULL;
>    442
>  > 443          num_sgs = sg_nents_for_dma(sgl, sg_len, chan-
> >max_length);
>    444          desc = axi_dmac_alloc_desc(num_sgs);
>    445          if (!desc)
>    446                  return NULL;
>    447
>    448          dsg = desc->sg;
>    449
>    450          for_each_sg(sgl, sg, sg_len, i) {
>    451                  if (!axi_dmac_check_addr(chan,
> sg_dma_address(sg)) ||
>    452                      !axi_dmac_check_len(chan, sg_dma_len(sg))) {
>    453                          kfree(desc);
>    454                          return NULL;
>    455                  }
>    456
>    457                  dsg = axi_dmac_fill_linear_sg(chan, direction,
> sg_dma_address(sg), 1,
>    458                          sg_dma_len(sg), dsg);
>    459          }
>    460
>    461          desc->cyclic = false;
>    462
>    463          return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags);
>    464  }
>    465
> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology
> Center
> https://lists.01.org/pipermail/kbuild-all                   Intel
> Corporation