From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753010AbcHZP2m (ORCPT ); Fri, 26 Aug 2016 11:28:42 -0400 Received: from mout.kundenserver.de ([212.227.126.135]:51553 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751139AbcHZP2k (ORCPT ); Fri, 26 Aug 2016 11:28:40 -0400 From: Arnd Bergmann To: linux-kernel@vger.kernel.org Cc: Linus Torvalds , Arnd Bergmann , Fushen Chen , Iyappan Subramanian , Keyur Chudgar , "David S. Miller" , netdev@vger.kernel.org Subject: [PATCH 5/5] net/xgene: fix error handling during reset Date: Fri, 26 Aug 2016 17:25:46 +0200 Message-Id: <20160826152546.604384-6-arnd@arndb.de> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20160826152546.604384-1-arnd@arndb.de> References: <20160826152546.604384-1-arnd@arndb.de> X-Provags-ID: V03:K0:1f1i6QSclAS/IaiwfXYVeXdjsL/JSbSg9WPTsZfma1G/CyHSKAN IvyQ1Vg6TdIoJPEKnyjUHtelVP5MmJK8L1CCDrJfHNOqsfxuQhH+iqSJkO/y+1icPiN4+qe 04jI/3gpDeh6Qg1TRtSjhia2FqSs93luoAyxpJ9JIkWS/hvwqpj1DmuMi/dgogxbXLuy+m3 ApoDQ9bu9fPY4LhDHAFgA== X-UI-Out-Filterresults: notjunk:1;V01:K0:9owz2pUcHMo=:41K1vDnGjeTYYVCoHJHgx7 O3xo23eDwCdKjxCPXZ3iDH20aCzLHWGCsGlb1+1mCNs5Ev4r3DQgCfqG2HiursmHHpMo31ui3 LuIVqFlpGVQbYf47PvHrwx0sg0ylUNYVdffKvOOF9CjTDa/U5gmIj/pc+oJVVAy8UwYYNO9ML UKtnXCyqQneid9lbtUiyf43o83j7vje0X8jgGx86NGcKw3TtjkklZp0V+WUWbLuutKeF9Njk7 SAYbvsTEcPQ018QbbHuL0EfEa+0WaUkcaQasIX9Wa6DGfRoHyCUt7o0xqtx4PZBXFIIVB/IeQ vLi5KMe0+Vrdd1PUFteyCw2y8wO9/PZEwnyt0oCkc1qwu7hgFw1i/uQ7nQ9IBP2GRLyYmlbjK 5sQLa4CN18t/6dbswsXvEWHgM+ukq2vucoGqsdBecPQd59GU0DhYi+w+eyAsZmRl4lHfQbAPc 6eCp7PR/mkGfghH4+LsGYpk5JcvO9r+dObk5rJbzIOIFCSF+e02B69IrIFGhLNL5K+FznRg5S s/uF2kj0taUPpF6TlqF6C9it1H7k3McIG6xXfmN3twZoeTOTd7JcdeZQhQhg9N5SEzim3qnZS j+eNeziIhvntUNSDyPPCTL5sssrmf79hNLVi0tazDiGK+ZPMaz3xEQWDQKPrZGS3Vj9NXB174 /enMKqdNMa+QJKVtAIxJYsKMBMIoMPTEtLyAjlruO4jHaEytRC2GK8FgsPRmA91Zxk4o= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The newly added reset logic uses helper functions for the MMIO that may fail. However, when the read operation fails, we end up writing back uninitialized data to the register, as gcc warns: drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c: In function 'xgene_enet_link_state': drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c:213:2: error: 'data' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c:209:6: note: 'data' was declared here u32 data; We already print a warning to the console log if that happens, the best alternative that I can see is skip the rest of the reset sequence if the register value cannot be read: Most likely the write would fail as well, and if it succeeded, worse things could happen. Signed-off-by: Arnd Bergmann Fixes: 3eb7cb9dc946 ("drivers: net: xgene: XFI PCS reset when link is down") Cc: Fushen Chen --- Cc: Iyappan Subramanian Cc: Keyur Chudgar Cc: "David S. Miller" Cc: netdev@vger.kernel.org drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c b/drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c index d672e71b5a50..279ee27004f7 100644 --- a/drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c +++ b/drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c @@ -155,19 +155,23 @@ static void xgene_enet_rd_mac(struct xgene_enet_pdata *pdata, rd_addr); } -static void xgene_enet_rd_pcs(struct xgene_enet_pdata *pdata, +static bool xgene_enet_rd_pcs(struct xgene_enet_pdata *pdata, u32 rd_addr, u32 *rd_data) { void __iomem *addr, *rd, *cmd, *cmd_done; + bool success; addr = pdata->pcs_addr + PCS_ADDR_REG_OFFSET; rd = pdata->pcs_addr + PCS_READ_REG_OFFSET; cmd = pdata->pcs_addr + PCS_COMMAND_REG_OFFSET; cmd_done = pdata->pcs_addr + PCS_COMMAND_DONE_REG_OFFSET; - if (!xgene_enet_rd_indirect(addr, rd, cmd, cmd_done, rd_addr, rd_data)) + success = xgene_enet_rd_indirect(addr, rd, cmd, cmd_done, rd_addr, rd_data); + if (!success) netdev_err(pdata->ndev, "PCS read failed, addr: %04x\n", rd_addr); + + return success; } static int xgene_enet_ecc_init(struct xgene_enet_pdata *pdata) @@ -208,7 +212,9 @@ static void xgene_pcs_reset(struct xgene_enet_pdata *pdata) { u32 data; - xgene_enet_rd_pcs(pdata, PCS_CONTROL_1, &data); + if (!xgene_enet_rd_pcs(pdata, PCS_CONTROL_1, &data)) + return; + xgene_enet_wr_pcs(pdata, PCS_CONTROL_1, data | PCS_CTRL_PCS_RST); xgene_enet_wr_pcs(pdata, PCS_CONTROL_1, data & ~PCS_CTRL_PCS_RST); } -- 2.9.0