From 9f2bc2c30d24987cff5edc43a3d8f89bef6ce12a Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Thu, 23 Oct 2014 10:25:53 +0200 Subject: [PATCH 07/11] drivers: net: xgene: Rewrite buggy loop in xgene_enet_ecc_init() Origin: https://git.kernel.org/linus/b71e821de50f0ff92f10f33064ee1713e9014158 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 Signed-off-by: David S. Miller --- drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c b/drivers/net/ethernet/apm/xgene/xgene_enet_sgmac.c index e6d24c2..c22f326 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) -- 2.1.0