Re: [net] Revert "net: wwan: mhi_wwan_mbim: Avoid -Wflex-array-member-not-at-end warning"

Re: [net] Revert "net: wwan: mhi_wwan_mbim: Avoid -Wflex-array-member-not-at-end warning"

[Gustavo A. R. Silva]

On 1/20/26 18:16, Slark Xiao wrote:
> 
> 
> At 2026-01-20 15:51:57, "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
>> Hi Slark,
>>
>> On 1/20/26 16:20, Slark Xiao wrote:
>>> This reverts commit eeecf5d3a3a484cedfa3f2f87e6d51a7390ed960.
>>>
>>> This change lead to MHI WWAN device can't connect to internet.
>>> I found a netwrok issue with kernel 6.19-rc4, but network works
>>> well with kernel 6.18-rc1. After checking, this commit is the
>>> root cause.
>>
>> Thanks for the report.
>>
>> Could you please apply the following patch on top of this revert,
>> and let us know if the problem still manifests? Thank you!
>>
>> diff --git a/drivers/net/wwan/mhi_wwan_mbim.c b/drivers/net/wwan/mhi_wwan_mbim.c
>> index 1d7e3ad900c1..a271a72fed63 100644
>> --- a/drivers/net/wwan/mhi_wwan_mbim.c
>> +++ b/drivers/net/wwan/mhi_wwan_mbim.c
>> @@ -78,9 +78,12 @@ struct mhi_mbim_context {
>>
>>   struct mbim_tx_hdr {
>>          struct usb_cdc_ncm_nth16 nth16;
>> -       struct usb_cdc_ncm_ndp16 ndp16;
>> -       struct usb_cdc_ncm_dpe16 dpe16[2];
>> +       __TRAILING_OVERLAP(struct usb_cdc_ncm_ndp16, ndp16, dpe16, __packed,
>> +               struct usb_cdc_ncm_dpe16 dpe16[2];
>> +       );
>>   } __packed;
>> +static_assert(offsetof(struct mbim_tx_hdr, ndp16.dpe16) ==
>> +             offsetof(struct mbim_tx_hdr, dpe16));
>>
>>   static struct mhi_mbim_link *mhi_mbim_get_link_rcu(struct mhi_mbim_context *mbim,
>>                                                     unsigned int session)
> This patch won't introduce previous problem.
> 

Thanks for confirming this.

I'll turn it into a proper patch.

-Gustavo

Re:Re: [net] Revert "net: wwan: mhi_wwan_mbim: Avoid -Wflex-array-member-not-at-end warning"

[Slark Xiao]

At 2026-01-20 17:28:42, "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
>
>
>On 1/20/26 18:16, Slark Xiao wrote:
>> 
>> 
>> At 2026-01-20 15:51:57, "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
>>> Hi Slark,
>>>
>>> On 1/20/26 16:20, Slark Xiao wrote:
>>>> This reverts commit eeecf5d3a3a484cedfa3f2f87e6d51a7390ed960.
>>>>
>>>> This change lead to MHI WWAN device can't connect to internet.
>>>> I found a netwrok issue with kernel 6.19-rc4, but network works
>>>> well with kernel 6.18-rc1. After checking, this commit is the
>>>> root cause.
>>>
>>> Thanks for the report.
>>>
>>> Could you please apply the following patch on top of this revert,
>>> and let us know if the problem still manifests? Thank you!
>>>
>>> diff --git a/drivers/net/wwan/mhi_wwan_mbim.c b/drivers/net/wwan/mhi_wwan_mbim.c
>>> index 1d7e3ad900c1..a271a72fed63 100644
>>> --- a/drivers/net/wwan/mhi_wwan_mbim.c
>>> +++ b/drivers/net/wwan/mhi_wwan_mbim.c
>>> @@ -78,9 +78,12 @@ struct mhi_mbim_context {
>>>
>>>   struct mbim_tx_hdr {
>>>          struct usb_cdc_ncm_nth16 nth16;
>>> -       struct usb_cdc_ncm_ndp16 ndp16;
>>> -       struct usb_cdc_ncm_dpe16 dpe16[2];
>>> +       __TRAILING_OVERLAP(struct usb_cdc_ncm_ndp16, ndp16, dpe16, __packed,
>>> +               struct usb_cdc_ncm_dpe16 dpe16[2];
>>> +       );
>>>   } __packed;
>>> +static_assert(offsetof(struct mbim_tx_hdr, ndp16.dpe16) ==
>>> +             offsetof(struct mbim_tx_hdr, dpe16));
>>>
>>>   static struct mhi_mbim_link *mhi_mbim_get_link_rcu(struct mhi_mbim_context *mbim,
>>>                                                     unsigned int session)
>> This patch won't introduce previous problem.
>> 
>
>Thanks for confirming this.
>
>I'll turn it into a proper patch.
>
>-Gustavo
Hi,
Are you planing to add this revert commit to your coming patch?
Actually it's urgent to revert this change since the release deadline of v6.19 is coming soon
and all my MHI WWAN device have been impacted.
I don't know why this commit has been tagged as "Not Applicable" and who did this.

I hope we can fix it regression before the official v6.19 release.

Thanks

Re: [net] Revert "net: wwan: mhi_wwan_mbim: Avoid -Wflex-array-member-not-at-end warning"

[Gustavo A. R. Silva]

On 1/22/26 10:30, Slark Xiao wrote:
> 
> 
> At 2026-01-20 17:28:42, "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
>>
>>
>> On 1/20/26 18:16, Slark Xiao wrote:
>>>
>>>
>>> At 2026-01-20 15:51:57, "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
>>>> Hi Slark,
>>>>
>>>> On 1/20/26 16:20, Slark Xiao wrote:
>>>>> This reverts commit eeecf5d3a3a484cedfa3f2f87e6d51a7390ed960.
>>>>>
>>>>> This change lead to MHI WWAN device can't connect to internet.
>>>>> I found a netwrok issue with kernel 6.19-rc4, but network works
>>>>> well with kernel 6.18-rc1. After checking, this commit is the
>>>>> root cause.
>>>>
>>>> Thanks for the report.
>>>>
>>>> Could you please apply the following patch on top of this revert,
>>>> and let us know if the problem still manifests? Thank you!
>>>>
>>>> diff --git a/drivers/net/wwan/mhi_wwan_mbim.c b/drivers/net/wwan/mhi_wwan_mbim.c
>>>> index 1d7e3ad900c1..a271a72fed63 100644
>>>> --- a/drivers/net/wwan/mhi_wwan_mbim.c
>>>> +++ b/drivers/net/wwan/mhi_wwan_mbim.c
>>>> @@ -78,9 +78,12 @@ struct mhi_mbim_context {
>>>>
>>>>    struct mbim_tx_hdr {
>>>>           struct usb_cdc_ncm_nth16 nth16;
>>>> -       struct usb_cdc_ncm_ndp16 ndp16;
>>>> -       struct usb_cdc_ncm_dpe16 dpe16[2];
>>>> +       __TRAILING_OVERLAP(struct usb_cdc_ncm_ndp16, ndp16, dpe16, __packed,
>>>> +               struct usb_cdc_ncm_dpe16 dpe16[2];
>>>> +       );
>>>>    } __packed;
>>>> +static_assert(offsetof(struct mbim_tx_hdr, ndp16.dpe16) ==
>>>> +             offsetof(struct mbim_tx_hdr, dpe16));
>>>>
>>>>    static struct mhi_mbim_link *mhi_mbim_get_link_rcu(struct mhi_mbim_context *mbim,
>>>>                                                      unsigned int session)
>>> This patch won't introduce previous problem.
>>>
>>
>> Thanks for confirming this.
>>
>> I'll turn it into a proper patch.
>>
>> -Gustavo
> Hi,
> Are you planing to add this revert commit to your coming patch?

No. I think the revert should be applied by the maintainers, first.

Thanks
-Gustavo

> Actually it's urgent to revert this change since the release deadline of v6.19 is coming soon
> and all my MHI WWAN device have been impacted.
> I don't know why this commit has been tagged as "Not Applicable" and who did this.
> 
> I hope we can fix it regression before the official v6.19 release.
> 
> Thanks

Re:Re: [net] Revert "net: wwan: mhi_wwan_mbim: Avoid -Wflex-array-member-not-at-end warning"

[Slark Xiao]

At 2026-01-22 10:14:41, "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
>
>
>On 1/22/26 10:30, Slark Xiao wrote:
>> 
>> 
>> At 2026-01-20 17:28:42, "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
>>>
>>>
>>> On 1/20/26 18:16, Slark Xiao wrote:
>>>>
>>>>
>>>> At 2026-01-20 15:51:57, "Gustavo A. R. Silva" <gustavo@embeddedor.com> wrote:
>>>>> Hi Slark,
>>>>>
>>>>> On 1/20/26 16:20, Slark Xiao wrote:
>>>>>> This reverts commit eeecf5d3a3a484cedfa3f2f87e6d51a7390ed960.
>>>>>>
>>>>>> This change lead to MHI WWAN device can't connect to internet.
>>>>>> I found a netwrok issue with kernel 6.19-rc4, but network works
>>>>>> well with kernel 6.18-rc1. After checking, this commit is the
>>>>>> root cause.
>>>>>
>>>>> Thanks for the report.
>>>>>
>>>>> Could you please apply the following patch on top of this revert,
>>>>> and let us know if the problem still manifests? Thank you!
>>>>>
>>>>> diff --git a/drivers/net/wwan/mhi_wwan_mbim.c b/drivers/net/wwan/mhi_wwan_mbim.c
>>>>> index 1d7e3ad900c1..a271a72fed63 100644
>>>>> --- a/drivers/net/wwan/mhi_wwan_mbim.c
>>>>> +++ b/drivers/net/wwan/mhi_wwan_mbim.c
>>>>> @@ -78,9 +78,12 @@ struct mhi_mbim_context {
>>>>>
>>>>>    struct mbim_tx_hdr {
>>>>>           struct usb_cdc_ncm_nth16 nth16;
>>>>> -       struct usb_cdc_ncm_ndp16 ndp16;
>>>>> -       struct usb_cdc_ncm_dpe16 dpe16[2];
>>>>> +       __TRAILING_OVERLAP(struct usb_cdc_ncm_ndp16, ndp16, dpe16, __packed,
>>>>> +               struct usb_cdc_ncm_dpe16 dpe16[2];
>>>>> +       );
>>>>>    } __packed;
>>>>> +static_assert(offsetof(struct mbim_tx_hdr, ndp16.dpe16) ==
>>>>> +             offsetof(struct mbim_tx_hdr, dpe16));
>>>>>
>>>>>    static struct mhi_mbim_link *mhi_mbim_get_link_rcu(struct mhi_mbim_context *mbim,
>>>>>                                                      unsigned int session)
>>>> This patch won't introduce previous problem.
>>>>
>>>
>>> Thanks for confirming this.
>>>
>>> I'll turn it into a proper patch.
>>>
>>> -Gustavo
>> Hi,
>> Are you planing to add this revert commit to your coming patch?
>
>No. I think the revert should be applied by the maintainers, first.
>
>Thanks
>-Gustavo
>
Hi Loic,
Could you help check this commit status?

Thanks
>> Actually it's urgent to revert this change since the release deadline of v6.19 is coming soon
>> and all my MHI WWAN device have been impacted.
>> I don't know why this commit has been tagged as "Not Applicable" and who did this.
>> 
>> I hope we can fix it regression before the official v6.19 release.
>> 
>> Thanks