On 4 Apr 2023, at 19:20, Sunil V L <sunilvl@xxxxxxxxxxxxxxxx> wrote: > > With CONFIG_ACPI enabled for RISC-V, this driver gets enabled > in allmodconfig build. However, RISC-V doesn't support sub-word > atomics which is used by this driver. Why not? Compilers and libatomic do, so surely the Linux kernel should too. > Due to this, the build fails > with below error. > > In function ‘ssh_seq_next’, > inlined from ‘ssam_request_write_data’ at drivers/platform/surface/aggregator/controller.c:1483:8: > ././include/linux/compiler_types.h:399:45: error: call to ‘__compiletime_assert_335’ declared with attribute error: BUILD_BUG failed > 399 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) > | ^ > ./include/linux/compiler.h:78:45: note: in definition of macro ‘unlikely’ > 78 | # define unlikely(x) __builtin_expect(!!(x), 0) > | ^ > ././include/linux/compiler_types.h:387:9: note: in expansion of macro ‘__compiletime_assert’ > 387 | __compiletime_assert(condition, msg, prefix, suffix) > | ^~~~~~~~~~~~~~~~~~~~ > ././include/linux/compiler_types.h:399:9: note: in expansion of macro ‘_compiletime_assert’ > 399 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) > | ^~~~~~~~~~~~~~~~~~~ > ./include/linux/build_bug.h:39:37: note: in expansion of macro ‘compiletime_assert’ > 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) > | ^~~~~~~~~~~~~~~~~~ > ./include/linux/build_bug.h:59:21: note: in expansion of macro ‘BUILD_BUG_ON_MSG’ > 59 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed") > | ^~~~~~~~~~~~~~~~ > ./arch/riscv/include/asm/cmpxchg.h:335:17: note: in expansion of macro ‘BUILD_BUG’ > 335 | BUILD_BUG(); \ > | ^~~~~~~~~ > ./arch/riscv/include/asm/cmpxchg.h:344:30: note: in expansion of macro ‘__cmpxchg’ > 344 | (__typeof__(*(ptr))) __cmpxchg((ptr), \ > | ^~~~~~~~~ > ./include/linux/atomic/atomic-instrumented.h:1916:9: note: in expansion of macro ‘arch_cmpxchg’ > 1916 | arch_cmpxchg(__ai_ptr, __VA_ARGS__); \ > | ^~~~~~~~~~~~ > drivers/platform/surface/aggregator/controller.c:61:32: note: in expansion of macro ‘cmpxchg’ > 61 | while (unlikely((ret = cmpxchg(&c->value, old, new)) != old)) { > | ^~~~~~~ > > So, disable this driver for RISC-V even when ACPI is enabled for now. > > Signed-off-by: Sunil V L <sunilvl@xxxxxxxxxxxxxxxx> > --- > drivers/platform/surface/aggregator/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/platform/surface/aggregator/Kconfig b/drivers/platform/surface/aggregator/Kconfig > index c114f9dd5fe1..88afc38ffdc5 100644 > --- a/drivers/platform/surface/aggregator/Kconfig > +++ b/drivers/platform/surface/aggregator/Kconfig > @@ -4,7 +4,7 @@ > menuconfig SURFACE_AGGREGATOR > tristate "Microsoft Surface System Aggregator Module Subsystem and Drivers" > depends on SERIAL_DEV_BUS > - depends on ACPI > + depends on ACPI && !RISCV If you insist on doing this, at least make it some new config variable that’s self-documenting and means this automatically gets re-enabled when arch/riscv fixes this deficiency? Hard-coding arch lists like this seems like a terrible anti-pattern. Jess > select CRC_CCITT > help > The Surface System Aggregator Module (Surface SAM or SSAM) is an > -- > 2.34.1 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-riscv