Re: [PATCH v4 09/11] xen/arm: smmuv3: Use fallthrough pseudo-keyword

[Rahul Singh <Rahul.Singh@xxxxxxx>]

Hello Stefano,

Thanks for reviewing the series.

> On 9 Jan 2021, at 1:44 am, Stefano Stabellini <sstabellini@xxxxxxxxxx> wrote:
> 
> On Fri, 8 Jan 2021, Rahul Singh wrote:
>> Merge the patch from linux to use fallthrough pseudo-keyword.
>> 
>> Replace the existing /* fall through */ comments and its variants with
>> the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
>> fall-through markings when it is the case.
>> 
>> Signed-off-by: Rahul Singh <rahul.singh@xxxxxxx>
>> ---
>> Changes in V4:
>> - This patch is introduce in this verison.
>> ---
>> xen/drivers/passthrough/arm/smmu-v3.c | 7 +++----
>> 1 file changed, 3 insertions(+), 4 deletions(-)
>> 
>> diff --git a/xen/drivers/passthrough/arm/smmu-v3.c 
>> b/xen/drivers/passthrough/arm/smmu-v3.c
>> index 5ce14850b4..f5f8b4c981 100644
>> --- a/xen/drivers/passthrough/arm/smmu-v3.c
>> +++ b/xen/drivers/passthrough/arm/smmu-v3.c
>> @@ -932,7 +932,6 @@ static void arm_smmu_cmdq_skip_err(struct 
>> arm_smmu_device *smmu)
>>               */
>>              return;
>>      case CMDQ_ERR_CERROR_ILL_IDX:
>> -            /* Fallthrough */
> 
> The fallthrough keyword is unnecessary here because of default, right?

Yes you are right fallthrough keyword is unnecessary here because  
"-Wimplicit-fallthrough” will not through the warning when a case label falls 
through to a case that breaks or returns.Therefore there is no need to have the 
fallthrough keyword here.

Regards,
Rahul

> 
> 
>>      default:
>>              break;
>>      }
>> @@ -2488,7 +2487,7 @@ static int arm_smmu_device_hw_probe(struct 
>> arm_smmu_device *smmu)
>>      switch (FIELD_GET(IDR0_STALL_MODEL, reg)) {
>>      case IDR0_STALL_MODEL_FORCE:
>>              smmu->features |= ARM_SMMU_FEAT_STALL_FORCE;
>> -            /* Fallthrough */
>> +            fallthrough;
>>      case IDR0_STALL_MODEL_STALL:
>>              smmu->features |= ARM_SMMU_FEAT_STALLS;
>>      }
>> @@ -2505,7 +2504,7 @@ static int arm_smmu_device_hw_probe(struct 
>> arm_smmu_device *smmu)
>>      switch (FIELD_GET(IDR0_TTF, reg)) {
>>      case IDR0_TTF_AARCH32_64:
>>              smmu->ias = 40;
>> -            /* Fallthrough */
>> +            fallthrough;
>>      case IDR0_TTF_AARCH64:
>>              break;
>>      default:
>> @@ -2589,7 +2588,7 @@ static int arm_smmu_device_hw_probe(struct 
>> arm_smmu_device *smmu)
>>      default:
>>              dev_info(smmu->dev,
>>                      "unknown output address size. Truncating to 48-bit\n");
>> -            /* Fallthrough */
>> +            fallthrough;
>>      case IDR5_OAS_48_BIT:
>>              smmu->oas = 48;
>>      }
>> -- 
>> 2.17.1