Re: [PATCH v2 09/13] dma/xlnx-zdma: Remove redundant statement in zdma_write_dst()

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 2/26/20 9:46 AM, kuhn.chenqun@huawei.com wrote:
> From: Chen Qun <kuhn.chenqun@huawei.com>
> 
> 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 <euler.robot@huawei.com>
> Signed-off-by: Chen Qun <kuhn.chenqun@huawei.com>
> ---
> Cc: Alistair Francis <alistair@alistair23.me>
> Cc: "Edgar E. Iglesias" <edgar.iglesias@gmail.com>
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
> 
> v1->v2: move the 'dst_type' declaration.(Base on Philippe's suggestion).
> ---
>   hw/dma/xlnx-zdma.c | 10 +++++-----
>   1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/hw/dma/xlnx-zdma.c b/hw/dma/xlnx-zdma.c
> index 8fb83f5b07..eeacad59ce 100644
> --- a/hw/dma/xlnx-zdma.c
> +++ b/hw/dma/xlnx-zdma.c
> @@ -373,7 +373,7 @@ static uint64_t zdma_update_descr_addr(XlnxZDMA *s, bool type,
>   static void zdma_write_dst(XlnxZDMA *s, uint8_t *buf, uint32_t len)
>   {
>       uint32_t dst_size, dlen;
> -    bool dst_intr, dst_type;
> +    bool dst_intr;
>       unsigned int ptype = ARRAY_FIELD_EX32(s->regs, ZDMA_CH_CTRL0, POINT_TYPE);
>       unsigned int rw_mode = ARRAY_FIELD_EX32(s->regs, ZDMA_CH_CTRL0, MODE);
>       unsigned int burst_type = ARRAY_FIELD_EX32(s->regs, ZDMA_CH_DATA_ATTR,
> @@ -387,17 +387,17 @@ static void zdma_write_dst(XlnxZDMA *s, uint8_t *buf, uint32_t len)
>       while (len) {
>           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);
>           if (dst_size == 0 && ptype == PT_MEM) {
>               uint64_t next;
> +            bool 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);
> -            dst_type = FIELD_EX32(s->dsc_dst.words[3], ZDMA_CH_DST_DSCR_WORD3,
> -                                  TYPE);
>           }
>   
>           /* Match what hardware does by ignoring the dst_size and only using
> 

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>