From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: Thu, 23 Oct 2014 08:25:53 +0000 (+0200)
Subject: drivers: net: xgene: Rewrite buggy loop in xgene_enet_ecc_init()
X-Git-Tag: firefly_0821_release~176^2~2938^2~37
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=b71e821de50f0ff92f10f33064ee1713e9014158;p=firefly-linux-kernel-4.4.55.git

drivers: net: xgene: Rewrite buggy loop in xgene_enet_ecc_init()

drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c: In function ‘xgene_enet_ecc_init’:
drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c:126: warning: ‘data’ may be used uninitialized in this function

Depending on the arbitrary value on the stack, the loop may terminate
too early, and cause a bogus -ENODEV failure.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c b/drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c
index e6d24c210198..c22f32622fa9 100644
--- a/drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c
+++ b/drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c
@@ -124,20 +124,18 @@ static int xgene_enet_ecc_init(struct xgene_enet_pdata *p)
 {
 	struct net_device *ndev = p->ndev;
 	u32 data;
-	int i;
+	int i = 0;
 
 	xgene_enet_wr_diag_csr(p, ENET_CFG_MEM_RAM_SHUTDOWN_ADDR, 0);
-	for (i = 0; i < 10 && data != ~0U ; i++) {
+	do {
 		usleep_range(100, 110);
 		data = xgene_enet_rd_diag_csr(p, ENET_BLOCK_MEM_RDY_ADDR);
-	}
+		if (data == ~0U)
+			return 0;
+	} while (++i < 10);
 
-	if (data != ~0U) {
-		netdev_err(ndev, "Failed to release memory from shutdown\n");
-		return -ENODEV;
-	}
-
-	return 0;
+	netdev_err(ndev, "Failed to release memory from shutdown\n");
+	return -ENODEV;
 }
 
 static void xgene_enet_config_ring_if_assoc(struct xgene_enet_pdata *p)