2023-11-01 11:52:36

by James Clark

Subject: [PATCH v2] coresight: etm4x: Fix width of CCITMIN field

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: [email protected]
Fixes: 2e1cdfe184b5 ("coresight-etm4x: Adding CoreSight ETM4x driver")
Reviewed-by: Mike Leach <[email protected]>
Signed-off-by: James Clark <[email protected]>
---

Changes since V1:
* Change the fixes commit to the original addition of ccitmin, rather
than the last refactor of the struct.

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

2023-11-01 13:23:42

by Suzuki K Poulose

Subject: Re: [PATCH v2] coresight: etm4x: Fix width of CCITMIN field

On 01/11/2023 11:52, 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: [email protected]
> Fixes: 2e1cdfe184b5 ("coresight-etm4x: Adding CoreSight ETM4x driver")
> Reviewed-by: Mike Leach <[email protected]>
> Signed-off-by: James Clark <[email protected]>

Thanks, applied to coresight next :


Suzuki