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Date:   Mon, 25 Oct 2021 11:03:59 +0530
From:   Vinod Koul <vkoul@kernel.org>
To:     Tim Gardner <tim.gardner@canonical.com>,
        Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Cc:     dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH][linux-next] dmaengine: dw-axi-dmac: Fix uninitialized
 variable in axi_chan_block_xfer_start()
Message-ID: <YXZBxx8NObaf3x70@matsya>
References: <20211019190701.15525-1-tim.gardner@canonical.com>
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On 19-10-21, 13:07, Tim Gardner wrote:
> Coverity complains of an uninitialized variable:
> 
> 5. uninit_use_in_call: Using uninitialized value config.dst_per when calling axi_chan_config_write. [show details]
> 6. uninit_use_in_call: Using uninitialized value config.hs_sel_src when calling axi_chan_config_write. [show details]
> CID 121164 (#1-3 of 3): Uninitialized scalar variable (UNINIT)
> 7. uninit_use_in_call: Using uninitialized value config.src_per when calling axi_chan_config_write. [show details]
> 418        axi_chan_config_write(chan, &config);
> 
> Fix this by clearing the structure which should at least be benign in axi_chan_config_write(). Also fix
> what looks like a cut-n-paste error when initializing config.hs_sel_dst.

Eugeniy?

> 
> Fixes: 824351668a413 ("dmaengine: dw-axi-dmac: support DMAX_NUM_CHANNELS > 8")
> Cc: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
> Cc: Vinod Koul <vkoul@kernel.org>
> Cc: dmaengine@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
> ---
>  drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> index 79572ec532ef..f47116e77ea1 100644
> --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
> @@ -386,12 +386,13 @@ static void axi_chan_block_xfer_start(struct axi_dma_chan *chan,
>  
>  	axi_dma_enable(chan->chip);
>  
> +	memset(&config, 0, sizeof(config));

pls init config while defining instead

        struct axi_dma_chan_config config = {};

>  	config.dst_multblk_type = DWAXIDMAC_MBLK_TYPE_LL;
>  	config.src_multblk_type = DWAXIDMAC_MBLK_TYPE_LL;
>  	config.tt_fc = DWAXIDMAC_TT_FC_MEM_TO_MEM_DMAC;
>  	config.prior = priority;
>  	config.hs_sel_dst = DWAXIDMAC_HS_SEL_HW;
> -	config.hs_sel_dst = DWAXIDMAC_HS_SEL_HW;
> +	config.hs_sel_src = DWAXIDMAC_HS_SEL_HW;
>  	switch (chan->direction) {
>  	case DMA_MEM_TO_DEV:
>  		dw_axi_dma_set_byte_halfword(chan, true);
> -- 
> 2.33.1

-- 
~Vinod