Re: next-20250903 x86_64 clang-20 allyesconfig mmp_pdma.c:1188:14: error: shift count >= width of type [-Werror,-Wshift-count-overflow]

From: Nathan Chancellor

Date: Wed Sep 17 2025 - 14:25:31 EST


Hi Guodong,

On Thu, Sep 04, 2025 at 03:38:21PM +0800, Guodong Xu wrote:
> On Thu, Sep 4, 2025 at 12:59 AM Nathan Chancellor <nathan@xxxxxxxxxx> wrote:
> >
> > On Wed, Sep 03, 2025 at 02:04:10PM +0200, Arnd Bergmann wrote:
> > > On Wed, Sep 3, 2025, at 12:08, Naresh Kamboju wrote:
> > >
> > > > Build error:
> > > > drivers/dma/mmp_pdma.c:1188:14: error: shift count >= width of type
> > > > [-Werror,-Wshift-count-overflow]
> > > > 1188 | .dma_mask = DMA_BIT_MASK(64), /* force 64-bit DMA
> > > > addr capability */
> > > > | ^~~~~~~~~~~~~~~~
> > > > include/linux/dma-mapping.h:73:54: note: expanded from macro 'DMA_BIT_MASK'
> > > > 73 | #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
> > > > | ^ ~~~
...
> Thanks, Arnd. I'll send a patch to clean up and simplify the logic.

This error continues to break our -next builds. Have you submitted this
patch yet? I searched lore.kernel.org and I did not find anything but I
wanted to make sure I had not missed anything.

Cheers,
Nathan