ACK/Cmnt: [SRU][Cosmic][Bionic][Xenial][PATCH 1/1] s390/qdio: reset old sbal_state flags

[Stefan Bader]

On 06.11.18 16:24, Frank Heimes wrote:
> From: Julian Wiedmann <jwi at linux.ibm.com <mailto:jwi at linux.ibm.com>>
> 
> BugLink: http://bugs.launchpad.net/bugs/1801686
> 
> s390/qdio: reset old sbal_state flags
>     
> When allocating a new AOB fails, handle_outbound() is still capable of
> transmitting the selected buffer (just without async completion).
>     
> But if a previous transfer on this queue slot used async completion, its
> sbal_state flags field is still set to QDIO_OUTBUF_STATE_FLAG_PENDING.
> So when the upper layer driver sees this stale flag, it expects an async
> completion that never happens.
>     
> Fix this by unconditionally clearing the flags field.
>     
> Fixes: 104ea556ee7f ("qdio: support asynchronous delivery of storage blocks")
> Cc: <stable at vger.kernel.org <mailto:stable at vger.kernel.org>> #v3.2+
> Signed-off-by: Julian Wiedmann <jwi at linux.ibm.com <mailto:jwi at linux.ibm.com>>
> Signed-off-by: Martin Schwidefsky <schwidefsky at de.ibm.com
> <mailto:schwidefsky at de.ibm.com>>
> (cherry picked from commit 64e03ff72623b8c2ea89ca3cb660094e019ed4ae)
> Signed-off-by: Frank Heimes <frank.heimes at canonical.com
> <mailto:frank.heimes at canonical.com>>
Acked-by: Stefan Bader <stefan.bader at canonical.com>
> 
> ---

As Kleber also said, those HTML emails get annoying. Frank, you should seriously
work on fixing that.

-Stefan
> 
> diff --git a/arch/s390/include/asm/qdio.h b/arch/s390/include/asm/qdio.h
> index de11ecc..9c9970a 100644
> --- a/arch/s390/include/asm/qdio.h
> +++ b/arch/s390/include/asm/qdio.h
> @@ -262,7 +262,6 @@ struct qdio_outbuf_state {
>         void *user;
>  };
>  
> -#define QDIO_OUTBUF_STATE_FLAG_NONE    0x00
>  #define QDIO_OUTBUF_STATE_FLAG_PENDING 0x01
>  
>  #define CHSC_AC1_INITIATE_INPUTQ       0x80
> diff --git a/drivers/s390/cio/qdio_main.c b/drivers/s390/cio/qdio_main.c
> index f4ca72d..9c7d9da 100644
> --- a/drivers/s390/cio/qdio_main.c
> +++ b/drivers/s390/cio/qdio_main.c
> @@ -631,21 +631,20 @@ static inline unsigned long qdio_aob_for_buffer(struct
> qdio_output_q *q,
>         unsigned long phys_aob = 0;
>  
>         if (!q->use_cq)
> -               goto out;
> +               return 0;
>  
>         if (!q->aobs[bufnr]) {
>                 struct qaob *aob = qdio_allocate_aob();
>                 q->aobs[bufnr] = aob;
>         }
>         if (q->aobs[bufnr]) {
> -               q->sbal_state[bufnr].flags = QDIO_OUTBUF_STATE_FLAG_NONE;
>                 q->sbal_state[bufnr].aob = q->aobs[bufnr];
>                 q->aobs[bufnr]->user1 = (u64) q->sbal_state[bufnr].user;
>                 phys_aob = virt_to_phys(q->aobs[bufnr]);
>                 WARN_ON_ONCE(phys_aob & 0xFF);
>         }
>  
> -out:
> +       q->sbal_state[bufnr].flags = 0;
>         return phys_aob;
>  }
> 


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