From: Arnd Bergmann <arnd@xxxxxxxx> [ 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@xxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 ce47eb17901d0..a106d15f6def0 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