On Wed, Apr 27, 2016 at 12:13:17PM +0530, Viresh Kumar wrote: > On 25-04-16, 15:35, Andy Shevchenko wrote: > > There are several changes are done here: > > > > - Convert the property to be in bytes > > > > Besides this is common practice for such property the use of a value in > > bytes > > much more convenient than handling the encoded value. > > > > - Rename data_width to data-width in the device tree bindings > > > > - While here, replace dwc_fast_ffs() by __ffs() > > > > The change leaves the support for old format as well just in case someone > > will > > use a newer kernel with an old device tree blob. > > > > Signed-off-by: Andy Shevchenko <andriy.shevche...@linux.intel.com> > > --- > > Documentation/devicetree/bindings/dma/snps-dma.txt | 6 ++-- > > arch/arc/boot/dts/abilis_tb10x.dtsi | 2 +- > > arch/arm/boot/dts/spear13xx.dtsi | 4 +-- > > drivers/dma/dw/core.c | 42 > > ++++++---------------- > > drivers/dma/dw/platform.c | 5 ++- > > include/linux/platform_data/dma-dw.h | 2 +- > > 6 files changed, 21 insertions(+), 40 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt > > b/Documentation/devicetree/bindings/dma/snps-dma.txt > > index c99c1ff..544b9b9 100644 > > --- a/Documentation/devicetree/bindings/dma/snps-dma.txt > > +++ b/Documentation/devicetree/bindings/dma/snps-dma.txt > > @@ -13,8 +13,8 @@ Required properties: > > - chan_priority: priority of channels. 0 (default): increase from chan > > 0->n, 1: > > increase from chan n->0 > > - block_size: Maximum block size supported by the controller > > -- data_width: Maximum data width supported by hardware per AHB master > > - (0 - 8bits, 1 - 16bits, ..., 5 - 256bits) > > +- data-width: Maximum data width supported by hardware per AHB master > > + (in bytes, power of 2) > > > > > > Optional properties: > > @@ -38,7 +38,7 @@ Example: > > chan_allocation_order = <1>; > > chan_priority = <1>; > > block_size = <0xfff>; > > - data_width = <3 3>; > > + data-width = <8 8>; > > }; > > You broke backward compatibility with earlier DTs. > > What's backward compatibility ? > > Consider that the DT from an earlier version of kernel is part of the bootrom > of > a SoC. Now that bootrom should work just fine with any new kernel version. > i.e. > old DT + new kernels should always work.
And this is not fixed yet!. -- ~Vinod
