spi: rockchip: initialize dma_slave_config properly

BugLink: https://bugs.launchpad.net/bugs/1853881

[ Upstream commit dd8fd2cb ]

The rxconf and txconf structs are allocated on the
stack, so make sure we zero them before filling out
the relevant fields.
Signed-off-by: Huibin Hong <huibin.hong@rock-chips.com>
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/spi/spi-rockchip.c

@@ -444,6 +444,9 @@ static void rockchip_spi_prepare_dma(struct rockchip_spi *rs)
 	struct dma_slave_config rxconf, txconf;
 	struct dma_async_tx_descriptor *rxdesc, *txdesc;
 
+	memset(&rxconf, 0, sizeof(rxconf));
+	memset(&txconf, 0, sizeof(txconf));
+
 	spin_lock_irqsave(&rs->lock, flags);
 	rs->state &= ~RXBUSY;
 	rs->state &= ~TXBUSY;