Alexey Kardashevskiy <aik@xxxxxxxxx> writes:
> On 19/12/2018 21:00, Michael Ellerman wrote:
>> Alexey Kardashevskiy <aik@xxxxxxxxx> writes:
>>> On 19/12/2018 11:17, Michael Ellerman wrote:
>>>> Alexey Kardashevskiy <aik@xxxxxxxxx> writes:
>>>>> diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c
>>>>> index dc629ee..3468eaa 100644
>>>>> --- a/arch/powerpc/platforms/powernv/npu-dma.c
>>>>> +++ b/arch/powerpc/platforms/powernv/npu-dma.c
>>>>> @@ -372,8 +358,263 @@ struct npu {
>>>> ...
>>>>> +
>>>>> +static void pnv_comp_attach_table_group(struct npu_comp *npucomp,
>>>>> + struct pnv_ioda_pe *pe)
>>>>> +{
>>>>> + if (WARN_ON(npucomp->pe_num == NV_NPU_MAX_PE_NUM))
>>>>> + return;
>>>>> +
>>>>> + npucomp->pe[npucomp->pe_num] = pe;
>>>>> + ++npucomp->pe_num;
>>>>> +}
>>>>> +
>>>>> +struct iommu_table_group *pnv_try_setup_npu_table_group(struct pnv_ioda_pe *pe)
>>>>> +{
>>>>> + struct iommu_table_group *table_group;
>>>>> + struct npu_comp *npucomp;
>>>>> + struct pci_dev *gpdev = NULL;
>>>>> + struct pci_controller *hose;
>>>>> + struct pci_dev *npdev;
>>>>> +
>>>>> + list_for_each_entry(gpdev, &pe->pbus->devices, bus_list) {
>>>>> + npdev = pnv_pci_get_npu_dev(gpdev, 0);
>>>>> + if (npdev)
>>>>> + break;
>>>>> + }
>>>>> +
>>>>> + if (!npdev)
>>>>> + /* It is not an NPU attached device, skip */
>>>>> + return NULL;
>>>>
>>>> This breaks some configs with:
>>>>
>>>> arch/powerpc/platforms/powernv/npu-dma.c:550:5: error: 'npdev' may be used uninitialized in this function [-Werror=uninitialized]
>>>
>>>
>>> gcc 5, 7 and 8 do not warn about this, I have to disable
>>> list_for_each_entry() above to recreate this.
>>>
>>> I even compiled gcc 5.5 which some of your buildmachines use and yet no
>>> error on this:
>>>
>>> make O=/home/aik/pbuild/kernel-le/ KCFLAGS=-Werror=all ARCH=powerpc
>>> CROSS_COMPILE=/opt/cross/gcc-powerpc64le-linux-5.5.0-nolibc/bin/powerpc64le-linux-
>>> arch/powerpc/platforms/powernv/npu-dma.o
>>
>> Odd. That error is from kisskb like the others.
>>
>> http://kisskb.ellerman.id.au/kisskb/buildresult/13622793/
>>
>> Seems it's GCC 4.6.3 that is producing that one. Not sure why newer
>> compilers aren't warning about it.
>>
>>
>> It's pretty obviously correct though, unless you can prove that the list
>> is never empty?
>
> I know these are correct and I want to catch these before I post patches :-/
>
> Can I get that gcc 4.6.3? It does not compile on my ubuntu for whatever
> reason.
It's the old korg one, it's on the ka's in /opt/cross.
It's this one:
https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86_64/4.6.3/x86_64-gcc-4.6.3-nolibc_powerpc64-linux.tar.xz
cheers
