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

[James Clark]

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 at vger.kernel.org
>> Fixes: 54ff892b76c6 ("coresight: etm4x: splitting struct etmv4_drvdata")
>> Signed-off-by: James Clark <james.clark at 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 at arm.com>