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

[Naresh Kamboju]

The following build warnings / errors were noticed on x86_64 allyesconfig
with clang-20 toolchain running on Linux next-20250903 tag.

But the gcc-13 builds passed.

Regression Analysis:
- New regression? yes
- Reproducibility? yes

First seen on next-20250903
Bad: next-20250903
Good: next-20250902

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

Reported-by: Linux Kernel Functional Testing <lkft@xxxxxxxxxx>

x86_64:
  build:
    * clang-20-allyesconfig

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))
      |                                                      ^ ~~~
1 error generated.
make[5]: *** [scripts/Makefile.build:287: drivers/dma/mmp_pdma.o] Error 1


## Source
* Kernel version: 6.17.0-rc4
* Git tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next.git
* Git describe: next-20250903
* Git commit: 5d50cf9f7cf20a17ac469c20a2e07c29c1f6aab7
* Architectures: x86_64
* Toolchains: clang-20
* Kconfigs: allyesconfig

## Build
* Build log: https://qa-reports.linaro.org/api/testruns/29752023/log_file/
* Build details:
https://regressions.linaro.org/lkft/linux-next-master/next-20250903/build/clang-20-allyesconfig/
* Build plan: https://tuxapi.tuxsuite.com/v1/groups/linaro/projects/lkft/builds/32B39xPuITjxcbak13h2MrLZJP4
* Build link: https://storage.tuxsuite.com/public/linaro/lkft/builds/32B39xPuITjxcbak13h2MrLZJP4/
* Kernel config:
https://storage.tuxsuite.com/public/linaro/lkft/builds/32B39xPuITjxcbak13h2MrLZJP4/config

--
Linaro LKFT
https://lkft.linaro.org