On Fri, Apr 08, 2016 at 11:28:01AM -0700, Guenter Roeck wrote: >On Fri, Apr 08, 2016 at 11:09:22AM -0400, William Breathitt Gray wrote: >> I feel now that the introduction of the ISA_BUS option may the wrong >> approach to resolve lack of ISA support for the X86_64 architecture; >> adding ISA_BUS depends or selects through various Kconfigs would simply >> obfuscate the ISA option. The true issue is that various driver >> configs are assuming X86_32 architecture when they depend on the ISA >> option, but the ISA bus does not require an X86_32 architecture. >> >> The proper resolution then is to remove the misguided ISA_BUS option and >> move the X86_32 dependency to the relevant drivers configs explicitly. >> A grep for isa_register_driver calls within the kernel reveals that only >> a few drivers explicitly use it. It should be trivial to create a patch >> to add the explicit X86_32 dependency to the relevant drivers, so I will >> submit one soon when I get the time to decouple X86_32 from the ISA >> config option. >> > >That might be tricky: At least some if not many of those drivers are expected >to run on non-X86 architectures, and thus don't really depend on X86_32 >(possibly some depend on 32 bit - I didn't check). > >I count 44 calls to isa_register_driver() in the current mainline. >Not sure if this counts as "only a few drivers". > >Thanks, >Guenter You're right, I there are more drivers that call isa_register_driver than I had estimated. I think a different approach may work however. When I initially proposed a patch to decouple the X86_32 dependency from the ISA config option, I received a reply from the 0-DAY kernel test auto-build indicating the errors from the drivers assuming a X86_32 architecture (http://www.gossamer-threads.com/lists/linux/kernel/2350122#2350122). After reviewing the debug messages, I realized there are only four main issues: 1. sound/isa/sscape.c:594:14: snd_printk format uses '%d' but a size_t is passed in 2. arch/x86/mm/extable.c:23:15: 'SEGMENT_IS_PNP_CODE' is undeclared 3. drivers/pnp/pnpbios/bioscall.c: a slew of undeclared symbols and casting type mismatches 4. drivers/scsi/ultrastor.c:674:29: sprintf format uses '%05X' but a kernel pointer is passed in Both issue 1 and issue 4 are easily fixed by patching the respective lines to match the format string with the variable type and vice-versa. Issue 2 and 3 are the actual X86_32 assumption I had suspected: these files depend on symbols declared in the include/asm/segment.h file; the declaration of these symbols is conditional: #ifdef CONFIG_X86_32. I believe this is the source of the issues I encountered on my initial attempt to decouple the X86_32 dependency from the ISA option. I suspect if I add an explicit X86_32 dependency to the PNPBIOS driver, I will be able to remove the X86_32 dependency from the ISA option without incident from the other drivers. William Breathitt Gray -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
