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From:   Tim Gardner <tim.gardner@canonical.com>
To:     vkoul@kernel.org
Cc:     tim.gardner@canonical.com,
        Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>,
        dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2][linux-next] dmaengine: dw-axi-dmac: Fix uninitialized variable in axi_chan_block_xfer_start()
Date:   Mon, 25 Oct 2021 12:16:56 -0600
Message-Id: <20211025181656.31658-1-tim.gardner@canonical.com>
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References: <YXZBxx8NObaf3x70@matsya>
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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 initializing the structure to 0 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.

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>
---

v2 - Use static initializer for 'config'. Drop the memset() call.

---
 drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

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..9a9194da0dcb 100644
--- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
+++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c
@@ -373,7 +373,7 @@ static void axi_chan_block_xfer_start(struct axi_dma_chan *chan,
 				      struct axi_dma_desc *first)
 {
 	u32 priority = chan->chip->dw->hdata->priority[chan->id];
-	struct axi_dma_chan_config config;
+	struct axi_dma_chan_config config = {};
 	u32 irq_mask;
 	u8 lms = 0; /* Select AXI0 master for LLI fetching */
 
@@ -391,7 +391,7 @@ static void axi_chan_block_xfer_start(struct axi_dma_chan *chan,
 	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