RE: [PATCH 09/13] dma/xlnx-zdma: Remove redundant statement in zdma_write_dst()

[Chenqun (kuhn)]

>-----Original Message-----
>From: Philippe Mathieu-Daudé [mailto:address@hidden]
>Sent: Tuesday, February 25, 2020 5:36 PM
>To: Chenqun (kuhn) <address@hidden>; qemu-
>address@hidden; address@hidden
>Cc: address@hidden; Zhanghailiang
><address@hidden>; Alistair Francis <address@hidden>;
>address@hidden
>Subject: Re: [PATCH 09/13] dma/xlnx-zdma: Remove redundant statement in
>zdma_write_dst()
>
>On 2/25/20 3:09 AM, address@hidden wrote:
>> From: Chen Qun <address@hidden>
>>
>> Clang static code analyzer show warning:
>> hw/dma/xlnx-zdma.c:399:13: warning: Value stored to 'dst_type' is never
>read
>>              dst_type = FIELD_EX32(s->dsc_dst.words[3],
>ZDMA_CH_DST_DSCR_WORD3,
>>              ^
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>
>> Reported-by: Euler Robot <address@hidden>
>> Signed-off-by: Chen Qun <address@hidden>
>> ---
>> Cc: Alistair Francis <address@hidden>
>> Cc: "Edgar E. Iglesias" <address@hidden>
>> Cc: Peter Maydell <address@hidden>
>> Cc: address@hidden
>> ---
>>   hw/dma/xlnx-zdma.c | 2 --
>>   1 file changed, 2 deletions(-)
>>
>> diff --git a/hw/dma/xlnx-zdma.c b/hw/dma/xlnx-zdma.c index
>> 8fb83f5b07..45355c5d59 100644
>> --- a/hw/dma/xlnx-zdma.c
>> +++ b/hw/dma/xlnx-zdma.c
>> @@ -396,8 +396,6 @@ static void zdma_write_dst(XlnxZDMA *s, uint8_t
>*buf, uint32_t len)
>>               zdma_load_descriptor(s, next, &s->dsc_dst);
>>               dst_size = FIELD_EX32(s->dsc_dst.words[2],
>ZDMA_CH_DST_DSCR_WORD2,
>>                                     SIZE);
>> -            dst_type = FIELD_EX32(s->dsc_dst.words[3],
>ZDMA_CH_DST_DSCR_WORD3,
>> -                                  TYPE);
>
>Maybe move dst_type to this if() statement now?
>
Sorry, I don't follow you.   I didn't find where I could move dst_type.
Do you mean to move the first dst_type to the if().  
Modify it like this:
    while (len) {
        dst_size = FIELD_EX32(s->dsc_dst.words[2], ZDMA_CH_DST_DSCR_WORD2,
                              SIZE);
        if (dst_size == 0 && ptype == PT_MEM) {
            uint64_t next;
            dst_type = FIELD_EX32(s->dsc_dst.words[3], ZDMA_CH_DST_DSCR_WORD3,
                              TYPE);
            next = zdma_update_descr_addr(s, dst_type,
                                          R_ZDMA_CH_DST_CUR_DSCR_LSB);
            zdma_load_descriptor(s, next, &s->dsc_dst);
            dst_size = FIELD_EX32(s->dsc_dst.words[2], ZDMA_CH_DST_DSCR_WORD2,
                                  SIZE);
        }
       ...
   }

Thanks.
>>           }
>>
>>           /* Match what hardware does by ignoring the dst_size and
>> only using
>>