With W=1 we see the following warning: | drivers/char/ipmi/ipmi_si_platform.c:272:15: error: \ | cast to smaller integer type 'enum si_type' from \ | 'const void *' [-Werror,-Wvoid-pointer-to-enum-cast] | 272 | io.si_type = (enum si_type) match->data; | | ^~~~~~~~~~~~~~~~~~~~~~~~~~
This is due to the fact that the `si_type` enum members are int-width and a cast from pointer-width down to int will cause truncation and possible data loss. Although in this case `si_type` has only a few enumerated fields and thus there is likely no data loss occurring. Nonetheless, this patch is necessary to the goal of promoting this warning out of W=1. Link: https://github.com/ClangBuiltLinux/linux/issues/1902 Link: https://lore.kernel.org/llvm/202308081000.ttl1eltr-...@intel.com/ Reported-by: kernel test robot <l...@intel.com> Signed-off-by: Justin Stitt <justinst...@google.com> --- Note: Arnd had mentioned that there perhaps may be some semantic differences between GCC and Clang regarding this warning or family of warnings. For now, this patch (and others following) will yield less noisy W=1 builds and hopefully materialize into this warning getting promoted out of W=1 to an always-on warning. --- drivers/char/ipmi/ipmi_si_platform.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/char/ipmi/ipmi_si_platform.c b/drivers/char/ipmi/ipmi_si_platform.c index 505cc978c97a..0d509d683c0f 100644 --- a/drivers/char/ipmi/ipmi_si_platform.c +++ b/drivers/char/ipmi/ipmi_si_platform.c @@ -269,7 +269,7 @@ static int of_ipmi_probe(struct platform_device *pdev) } memset(&io, 0, sizeof(io)); - io.si_type = (enum si_type) match->data; + io.si_type = (unsigned long) match->data; io.addr_source = SI_DEVICETREE; io.irq_setup = ipmi_std_irq_setup; --- base-commit: c1a515d3c0270628df8ae5f5118ba859b85464a2 change-id: 20230809-cbl-1902-7532a747b731 Best regards, -- Justin Stitt <justinst...@google.com> _______________________________________________ Openipmi-developer mailing list Openipmi-developer@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openipmi-developer
