| Message ID | 20231030102940.115078-1-james.clark@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: etm4x: Fix width of CCITMIN field | expand |
On Mon, 30 Oct 2023 at 10:29, James Clark <james.clark@arm.com> wrote: > > CCITMIN is a 12 bit field and doesn't fit in a u8, so extend it to u16. > This probably wasn't an issue previously because values higher than 255 > never occurred. > > But since commit 0f55b43dedcd ("coresight: etm: Override TRCIDR3.CCITMIN > on errata affected cpus"), a comparison with 256 was done to enable the > errata, generating the following W=1 build error: > > coresight-etm4x-core.c:1188:24: error: result of comparison of > constant 256 with expression of type 'u8' (aka 'unsigned char') is > always false [-Werror,-Wtautological-constant-out-of-range-compare] > > if (drvdata->ccitmin == 256) > > Cc: stable@vger.kernel.org > Fixes: 54ff892b76c6 ("coresight: etm4x: splitting struct etmv4_drvdata") > Signed-off-by: James Clark <james.clark@arm.com> > --- > drivers/hwtracing/coresight/coresight-etm4x.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h > index 20e2e4cb7614..da17b6c49b0f 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x.h > +++ b/drivers/hwtracing/coresight/coresight-etm4x.h > @@ -1036,7 +1036,7 @@ struct etmv4_drvdata { > u8 ctxid_size; > u8 vmid_size; > u8 ccsize; > - u8 ccitmin; > + u16 ccitmin; > u8 s_ex_level; > u8 ns_ex_level; > u8 q_support; > -- > 2.34.1 > Reviewed-by: Mike Leach <mike.leach@linaro.org>
On 10/30/23 15:59, James Clark wrote: > CCITMIN is a 12 bit field and doesn't fit in a u8, so extend it to u16. > This probably wasn't an issue previously because values higher than 255 > never occurred. > > But since commit 0f55b43dedcd ("coresight: etm: Override TRCIDR3.CCITMIN > on errata affected cpus"), a comparison with 256 was done to enable the > errata, generating the following W=1 build error: > > coresight-etm4x-core.c:1188:24: error: result of comparison of > constant 256 with expression of type 'u8' (aka 'unsigned char') is > always false [-Werror,-Wtautological-constant-out-of-range-compare] > > if (drvdata->ccitmin == 256) > > Cc: stable@vger.kernel.org > Fixes: 54ff892b76c6 ("coresight: etm4x: splitting struct etmv4_drvdata") > Signed-off-by: James Clark <james.clark@arm.com> > --- > drivers/hwtracing/coresight/coresight-etm4x.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h > index 20e2e4cb7614..da17b6c49b0f 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x.h > +++ b/drivers/hwtracing/coresight/coresight-etm4x.h > @@ -1036,7 +1036,7 @@ struct etmv4_drvdata { > u8 ctxid_size; > u8 vmid_size; > u8 ccsize; > - u8 ccitmin; > + u16 ccitmin; > u8 s_ex_level; > u8 ns_ex_level; > u8 q_support; Thanks James, so this takes care of the Smatch static checker warning as reported by Dan Carpenter earlier. Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
On 02/11/2023 04:14, Anshuman Khandual wrote: > > > On 10/30/23 15:59, James Clark wrote: >> CCITMIN is a 12 bit field and doesn't fit in a u8, so extend it to u16. >> This probably wasn't an issue previously because values higher than 255 >> never occurred. >> >> But since commit 0f55b43dedcd ("coresight: etm: Override TRCIDR3.CCITMIN >> on errata affected cpus"), a comparison with 256 was done to enable the >> errata, generating the following W=1 build error: >> >> coresight-etm4x-core.c:1188:24: error: result of comparison of >> constant 256 with expression of type 'u8' (aka 'unsigned char') is >> always false [-Werror,-Wtautological-constant-out-of-range-compare] >> >> if (drvdata->ccitmin == 256) >> >> Cc: stable@vger.kernel.org >> Fixes: 54ff892b76c6 ("coresight: etm4x: splitting struct etmv4_drvdata") >> Signed-off-by: James Clark <james.clark@arm.com> >> --- >> drivers/hwtracing/coresight/coresight-etm4x.h | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h >> index 20e2e4cb7614..da17b6c49b0f 100644 >> --- a/drivers/hwtracing/coresight/coresight-etm4x.h >> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h >> @@ -1036,7 +1036,7 @@ struct etmv4_drvdata { >> u8 ctxid_size; >> u8 vmid_size; >> u8 ccsize; >> - u8 ccitmin; >> + u16 ccitmin; >> u8 s_ex_level; >> u8 ns_ex_level; >> u8 q_support; > > Thanks James, so this takes care of the Smatch static checker > warning as reported by Dan Carpenter earlier. > I didn't see that report, but it was in "[linux-next:master] BUILD REGRESSION c503e3eec382ac708ee7adf874add37b77c5d312" > Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h index 20e2e4cb7614..da17b6c49b0f 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.h +++ b/drivers/hwtracing/coresight/coresight-etm4x.h @@ -1036,7 +1036,7 @@ struct etmv4_drvdata { u8 ctxid_size; u8 vmid_size; u8 ccsize; - u8 ccitmin; + u16 ccitmin; u8 s_ex_level; u8 ns_ex_level; u8 q_support;
CCITMIN is a 12 bit field and doesn't fit in a u8, so extend it to u16. This probably wasn't an issue previously because values higher than 255 never occurred. But since commit 0f55b43dedcd ("coresight: etm: Override TRCIDR3.CCITMIN on errata affected cpus"), a comparison with 256 was done to enable the errata, generating the following W=1 build error: coresight-etm4x-core.c:1188:24: error: result of comparison of constant 256 with expression of type 'u8' (aka 'unsigned char') is always false [-Werror,-Wtautological-constant-out-of-range-compare] if (drvdata->ccitmin == 256) Cc: stable@vger.kernel.org Fixes: 54ff892b76c6 ("coresight: etm4x: splitting struct etmv4_drvdata") Signed-off-by: James Clark <james.clark@arm.com> --- drivers/hwtracing/coresight/coresight-etm4x.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)