On Fri, 2020-01-31 at 23:36 +0100, Dimitry Andric wrote: > Hmm yes, you are quite right. Other parts of the code also seem to > use ~TPM_XXX, and the WR4() inline function called takes a > uint32_t. I'll revert my change and apply the tilde version instead! > > -Dimitry >
So you're going to switch from writing 0 to writing 0xfffffffe, and just assume that will work the same? Like, without looking at the datasheet or TRM for the device? Surely those other 31 bits you're turning on in a control register can't do anything important, can they? I haven't looked at the code, but I'll bet the other places that are using ~SYMBOLNAME are doing so in the context of read-modify-write in a way that preserves existing bits, which is completely different than just turning on 31 bits as a side effect of turning one bit off. -- Ian > > On 31 Jan 2020, at 22:13, Conrad Meyer <c...@freebsd.org> wrote: > > > > Hi Dimitry, > > > > Do you think maybe the intent is to use ~TPM_CRB_CTRL_CANCEL_CMD > > instead? Plain "0" might also make sense. But I think the > > compiler > > is right here and the warning should not be disabled — !BIT(foo) > > doesn't really make sense for a register. It happens to affect the > > right bit only because CANCEL_CMD is BIT(0). > > > > Thanks, > > Conrad > > > > On Fri, Jan 31, 2020 at 11:36 AM Dimitry Andric <d...@freebsd.org> > > wrote: > > > > > > Author: dim > > > Date: Fri Jan 31 19:36:14 2020 > > > New Revision: 357349 > > > URL: https://svnweb.freebsd.org/changeset/base/357349 > > > > > > Log: > > > Merge r357348 from the clang 10.0.0 import branch: > > > > > > Disable new clang 10.0.0 warnings about converting the result of > > > shift > > > operations to a boolean in tpm(4): > > > > > > sys/dev/tpm/tpm_crb.c:301:32: error: converting the result of > > > '<<' to a boolean; did you mean '(1 << (0)) != 0'? [-Werror,- > > > Wint-in-bool-context] > > > WR4(sc, TPM_CRB_CTRL_CANCEL, !TPM_CRB_CTRL_CANCEL_CMD); > > > ^ > > > sys/dev/tpm/tpm_crb.c:73:34: note: expanded from macro > > > 'TPM_CRB_CTRL_CANCEL_CMD' > > > #define TPM_CRB_CTRL_CANCEL_CMD BIT(0) > > > ^ > > > sys/dev/tpm/tpm20.h:60:19: note: expanded from macro 'BIT' > > > #define BIT(x) (1 << (x)) > > > ^ > > > > > > Such warnings can be useful in C++ contexts, but not so much in > > > kernel > > > drivers, where this type of bit twiddling is commonplace. So > > > disable it > > > for this case. > > > > > > MFC after: 3 days > > > > > > Modified: > > > head/sys/conf/files.amd64 > > > head/sys/conf/kern.mk > > > head/sys/modules/tpm/Makefile > > > Directory Properties: > > > head/ (props changed) > > > > > > Modified: head/sys/conf/files.amd64 > > > ================================================================= > > > ============= > > > --- head/sys/conf/files.amd64 Fri Jan 31 19:35:21 > > > 2020 (r357348) > > > +++ head/sys/conf/files.amd64 Fri Jan 31 19:36:14 > > > 2020 (r357349) > > > @@ -323,7 +323,8 @@ > > > dev/syscons/scvesactl.c optional sc vga vesa > > > dev/syscons/scvgarndr.c optional sc vga > > > dev/tpm/tpm.c optional tpm > > > dev/tpm/tpm20.c optional tpm > > > -dev/tpm/tpm_crb.c optional tpm acpi > > > +dev/tpm/tpm_crb.c optional tpm acpi \ > > > + compile-with "${NORMAL_C} ${NO_WINT_IN_BOOL_CONTEXT}" > > > dev/tpm/tpm_tis.c optional tpm acpi > > > dev/tpm/tpm_acpi.c optional tpm acpi > > > dev/tpm/tpm_isa.c optional tpm isa > > > > > > Modified: head/sys/conf/kern.mk > > > ================================================================= > > > ============= > > > --- head/sys/conf/kern.mk Fri Jan 31 19:35:21 > > > 2020 (r357348) > > > +++ head/sys/conf/kern.mk Fri Jan 31 19:36:14 > > > 2020 (r357349) > > > @@ -37,6 +37,9 @@ CWARNEXTRA+= -Wno-error-shift-negative-value > > > .if ${COMPILER_VERSION} >= 40000 > > > CWARNEXTRA+= -Wno-address-of-packed-member > > > .endif > > > +.if ${COMPILER_VERSION} >= 100000 > > > +NO_WINT_IN_BOOL_CONTEXT= -Wno-int-in-bool-context > > > +.endif > > > .endif > > > > > > .if ${COMPILER_TYPE} == "gcc" > > > > > > Modified: head/sys/modules/tpm/Makefile > > > ================================================================= > > > ============= > > > --- head/sys/modules/tpm/Makefile Fri Jan 31 19:35:21 > > > 2020 (r357348) > > > +++ head/sys/modules/tpm/Makefile Fri Jan 31 19:36:14 > > > 2020 (r357349) > > > @@ -11,3 +11,5 @@ SRCS+= tpm_isa.c tpm_acpi.c isa_if.h > > > opt_acpi.h acpi_i > > > SRCS+= tpm20.c tpm_crb.c tpm_tis.c opt_tpm.h > > > > > > .include <bsd.kmod.mk> > > > + > > > +CWARNFLAGS.tpm_crb.c+= ${NO_WINT_IN_BOOL_CONTEXT} > > _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
