Subject: Re: linux-next: manual merge of the dmaengine tree with the dmaengine-fixes tree

From: Dave Jiang <[email-masked]>
Date: Tue, 4 Jan 2022 14:41:00 -0700

On 12/28/2021 2:09 AM, Geert Uytterhoeven wrote:
> On Wed, Dec 15, 2021 at 10:53 AM <[email-masked]> wrote:
>> Today's linux-next merge of the dmaengine tree got a conflict in:
>>
>>    drivers/dma/idxd/submit.c
>>
>> between commit:
>>
>>    8affd8a4b5ce3 ("dmaengine: idxd: fix missed completion on abort path")
>>
>> from the dmaengine-fixes tree and commit:
>>
>>    5d78abb6fbc97 ("dmaengine: idxd: rework descriptor free path on failure")
>>
>> from the dmaengine tree.
>>
>> I fixed it up (see below) and can carry the fix as necessary. This
>> is now fixed as far as linux-next is concerned, but any non trivial
>> conflicts should be mentioned to your upstream maintainer when your tree
>> is submitted for merging.  You may also want to consider cooperating
>> with the maintainer of the conflicting tree to minimise any particularly
>> complex conflicts.
>>
>> diff --cc drivers/dma/idxd/submit.c
>> index 83452fbbb168b,569815a84e95b..0000000000000
>> --- a/drivers/dma/idxd/submit.c
>> +++ b/drivers/dma/idxd/submit.c
>> @@@ -134,20 -120,32 +125,43 @@@ static void llist_abort_desc(struct idx
>>          spin_unlock(&ie->list_lock);
>>
>>          if (found)
>> -               complete_desc(found, IDXD_COMPLETE_ABORT);
>> +               idxd_dma_complete_txd(found, IDXD_COMPLETE_ABORT, false);
>>   +
>>   +      /*
>> -        * complete_desc() will return desc to allocator and the desc can be
>> -        * acquired by a different process and the desc->list can be modified.
>> -        * Delete desc from list so the list trasversing does not get corrupted
>> -        * by the other process.
>> ++       * completing the descriptor will return desc to allocator and
>> ++       * the desc can be acquired by a different process and the
>> ++       * desc->list can be modified.  Delete desc from list so the
>> ++       * list trasversing does not get corrupted by the other process.
> traversing
>
>>   +       */
>>   +      list_for_each_entry_safe(d, t, &flist, list) {
>>   +              list_del_init(&d->list);
>> -               complete_desc(d, IDXD_COMPLETE_NORMAL);
>> ++              idxd_dma_complete_txd(d, IDXD_COMPLETE_NORMAL, false);
> Is "false" correct here?

Hi Geert, took a closer look today. I believe it should be 'true' here 
since this is a normal completion that needs to release the descriptors. 
Sorry about the previous incorrect response.

>
>>   +      }
>>    }
> Gr{oetje,eeting}s,
>
>                          Geert
>
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- [email-masked]
>
> In personal conversations with technical people, I call myself a hacker. But
> when I'm talking to journalists I just say "programmer" or something like that.
>                                  -- Linus Torvalds