Re: [PATCH arm/aspeed/ast2500 v4 1/2] ipmi: add a KCS IPMI BMC driver

[Corey Minyard]

On 02/01/2018 07:33 PM, Wang, Haiyue wrote:
> On 2018-02-02 09:10, Corey Minyard wrote:
> > I loaded this in, tried a compile on x86_64, and got the following:
> >
> > In file included from ../drivers/char/ipmi/kcs_bmc.c:15:0:
> > ../drivers/char/ipmi/kcs_bmc.h: In function âkcs_bmc_privâ:
> > ../drivers/char/ipmi/kcs_bmc.h:100:9: warning: return discards 
> > âconstâ qualifier from pointer target type [-Wdiscarded-qualifiers]
> > Â return kcs_bmc->priv;
> > ÂÂÂÂÂÂÂÂ ^
> -static inline void *kcs_bmc_priv(const struct kcs_bmc *kcs_bmc)
> +static inline void *kcs_bmc_priv(struct kcs_bmc *kcs_bmc)Â <-- Can 
> this fix error on x86_64 ?
> {
> ÂÂÂ return kcs_bmc->priv;
> }

That, or you can separately alloc the priv data and just make it a 
pointer. That's more standard, but either way will work.

Where you not getting this warning on your compile?

> > In file included from ../include/linux/printk.h:7:0,
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ from ../include/linux/kernel.h:14,
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ from ../include/asm-generic/bug.h:18,
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ from ../arch/x86/include/asm/bug.h:82,
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ from ../include/linux/bug.h:5,
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ from ../include/linux/io.h:23,
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ from ../drivers/char/ipmi/kcs_bmc.c:7:
> > ../drivers/char/ipmi/kcs_bmc.c: In function âkcs_bmc_readâ:
> > ../include/linux/kern_levels.h:5:18: warning: format â%uâ expects 
> > argument of type âunsigned intâ, but argument 3 has type âsize_t {aka 
> > long unsigned int}â [-Wformat=]
> > Â#define KERN_SOH "\001"Â /* ASCII Start Of Header */
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ ^
> > ../include/linux/kern_levels.h:11:18: note: in expansion of macro 
> > âKERN_SOHâ
> > Â#define KERN_ERR KERN_SOH "3" /* error conditions */
> > ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ ^
> > ../include/linux/printk.h:301:9: note: in expansion of macro âKERN_ERRâ
> > Â printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
> > ÂÂÂÂÂÂÂÂ ^
> > ../drivers/char/ipmi/kcs_bmc.c:307:3: note: in expansion of macro 
> > âpr_errâ
> > ÂÂ pr_err("channel=%u with too large data : %u\n",
> > ÂÂ ^
> https://elinux.org/Debugging_by_printing
> However please*note*: always use/%zu/,/%zd/or/%zx/for 
> printing/size_t/and/ssize_t/values. ssize_t and size_t are quite 
> common values in the kernel, so please use the/%z/to avoid annoying 
> compile warnings.
> So I change it from "%u" to "%zu", it is passed on my arm-32 compile, 
> is it OK on your X64 ?

Should be good.

Thanks,

-corey

> pr_err("channel=%u with too large data : %zu\n",
> > In file included from ../drivers/char/ipmi/kcs_bmc_aspeed.c:20:0:
> > ../drivers/char/ipmi/kcs_bmc.h: In function âkcs_bmc_privâ:
> > ../drivers/char/ipmi/kcs_bmc.h:100:9: warning: return discards 
> > âconstâ qualifier from pointer target type [-Wdiscarded-qualifiers]
> > Â return kcs_bmc->priv;
> > ÂÂÂÂÂÂÂÂ ^
> >
> > So that needs to be fixed before it goes in.
> >
> > Also, since you are respinning, can you make ASPEED_KCS_IPMI_BMC 
> > select IPMI_KCS_BMC, like:
> >
> > diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
> > index bc2568a..d34f40e 100644
> > --- a/drivers/char/ipmi/Kconfig
> > +++ b/drivers/char/ipmi/Kconfig
> > @@ -99,16 +99,11 @@ config IPMI_POWEROFF
> > Âendif # IPMI_HANDLER
> >
> > Âconfig IPMI_KCS_BMC
> > -ÂÂÂÂÂÂ tristate 'IPMI KCS BMC Interface'
> > -ÂÂÂÂÂÂ help
> > -ÂÂÂÂÂÂÂÂ Provides a device driver for the KCS (Keyboard Controller 
> > Style)
> > -ÂÂÂÂÂÂÂÂ IPMI interface which meets the requirement of the BMC 
> > (Baseboard
> > -ÂÂÂÂÂÂÂÂ Management Controllers) side for handling the IPMI request 
> > from
> > -ÂÂÂÂÂÂÂÂ host system software.
> > +ÂÂÂÂÂÂ tristate
> >
> > Âconfig ASPEED_KCS_IPMI_BMC
> > ÂÂÂÂÂÂÂ depends on ARCH_ASPEED || COMPILE_TEST
> > -ÂÂÂÂÂÂ depends on IPMI_KCS_BMC
> > +ÂÂÂÂÂÂ select IPMI_KCS_BMC
> > ÂÂÂÂÂÂÂ select REGMAP_MMIO
> > ÂÂÂÂÂÂÂ tristate "Aspeed KCS IPMI BMC driver"
> > ÂÂÂÂÂÂÂ help
> >
> > It doesn't make much sense to have IPMI_KCS_BMC on its own. I was 
> > going to do this till I saw the compiler error.
> Got it, will change it to 'select'
> > -corey