Re: [PATCH 4/5] esp: revert 75ef849696 "esp: correctly fill bus id with requested lun"

[Paolo Bonzini <pbonzini@redhat.com>]

On 09/06/21 17:31, Mark Cave-Ayland wrote:
> Due to the absence of the IDENTIFY byte in the S case I'm guessing from 
> the patch that the LUN is in encoded in buf[1] (the top bits being 
> "Reserved" according to my copy of the specification).

They used to be the LUN many years ago.

>   static void s_without_satn_pdma_cb(ESPState *s)
>   {
> +    uint8_t busid;
> +
>       if (!esp_get_tc(s) && !fifo8_is_empty(&s->cmdfifo)) {
>           s->cmdfifo_cdb_offset = 0;
>           s->do_cmd = 0;
> -        do_busid_cmd(s, 0);
> +        busid = s->cmdfifo.data[1] >> 5;
> +        do_busid_cmd(s, busid);
>       }
>   }

Considering how obsolete the LUN-in-CDB case is (and now that I actually 
understand that the first byte is a message-phase byte), it is probably 
be more correct to keep the previous busid: with no message phase, the 
previously-selected LUN would be addressed.  I can send a patch for 
this, but it's orthogonal to this one so I queued it as well.

Paolo