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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 39/55] atm: eni: fix uninitialized variable warning
Date:   Thu, 30 Jan 2020 19:39:20 +0100
Message-Id: <20200130183615.555864002@linuxfoundation.org>
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From: Arnd Bergmann <arnd@arndb.de>

[ Upstream commit 30780d086a83332adcd9362281201cee7c3d9d19 ]

With -O3, gcc has found an actual unintialized variable stored
into an mmio register in two instances:

drivers/atm/eni.c: In function 'discard':
drivers/atm/eni.c:465:13: error: 'dma[1]' is used uninitialized in this function [-Werror=uninitialized]
   writel(dma[i*2+1],eni_dev->rx_dma+dma_wr*8+4);
             ^
drivers/atm/eni.c:465:13: error: 'dma[3]' is used uninitialized in this function [-Werror=uninitialized]

Change the code to always write zeroes instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/atm/eni.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/atm/eni.c b/drivers/atm/eni.c
index 6470e3c4c9907..7323e9210f4b1 100644
--- a/drivers/atm/eni.c
+++ b/drivers/atm/eni.c
@@ -372,7 +372,7 @@ static int do_rx_dma(struct atm_vcc *vcc,struct sk_buff *skb,
 		here = (eni_vcc->descr+skip) & (eni_vcc->words-1);
 		dma[j++] = (here << MID_DMA_COUNT_SHIFT) | (vcc->vci
 		    << MID_DMA_VCI_SHIFT) | MID_DT_JK;
-		j++;
+		dma[j++] = 0;
 	}
 	here = (eni_vcc->descr+size+skip) & (eni_vcc->words-1);
 	if (!eff) size += skip;
@@ -445,7 +445,7 @@ static int do_rx_dma(struct atm_vcc *vcc,struct sk_buff *skb,
 	if (size != eff) {
 		dma[j++] = (here << MID_DMA_COUNT_SHIFT) |
 		    (vcc->vci << MID_DMA_VCI_SHIFT) | MID_DT_JK;
-		j++;
+		dma[j++] = 0;
 	}
 	if (!j || j > 2*RX_DMA_BUF) {
 		printk(KERN_CRIT DEV_LABEL "!j or j too big!!!\n");
-- 
2.20.1