From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933320AbcHYIIT (ORCPT ); Thu, 25 Aug 2016 04:08:19 -0400 Received: from lucky1.263xmail.com ([211.157.147.133]:47936 "EHLO lucky1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753868AbcHYIIS (ORCPT ); Thu, 25 Aug 2016 04:08:18 -0400 X-263anti-spam: KSV:0; X-MAIL-GRAY: 1 X-MAIL-DELIVERY: 0 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-ADDR-CHECKED: 0 X-RL-SENDER: shawn.lin@rock-chips.com X-FST-TO: bhelgaas@google.com X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: shawn.lin@rock-chips.com X-UNIQUE-TAG: <1f56c9cb05a6073efc3ed8403ba23c61> X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 From: Shawn Lin To: Bjorn Helgaas Cc: linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Brian Norris , Shawn Lin Subject: [PATCH 1/2] PCI: rockchip: fix broken ASPM due to incorrect L1PwrOnSc/Val Date: Thu, 25 Aug 2016 16:03:34 +0800 Message-Id: <1472112214-31550-1-git-send-email-shawn.lin@rock-chips.com> X-Mailer: git-send-email 1.8.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is a bug of controller found recently which makes the default values of L1PwrOnSc and L1PwrOnVal unreliable when enabling ASPM. We could work around this by reading L1 substate control 2 register and then write back the value again. Signed-off-by: Shawn Lin --- drivers/pci/host/pcie-rockchip.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/pci/host/pcie-rockchip.c b/drivers/pci/host/pcie-rockchip.c index 1671d02..ed782b51 100644 --- a/drivers/pci/host/pcie-rockchip.c +++ b/drivers/pci/host/pcie-rockchip.c @@ -40,6 +40,7 @@ #define PCIE_CLIENT_BASE 0x0 #define PCIE_RC_CONFIG_NORMAL_BASE 0x800000 #define PCIE_RC_CONFIG_BASE 0xa00000 +#define PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2 0x90c #define PCIE_RC_CONFIG_LCSR 0xd0 #define PCIE_RC_CONFIG_LCSR_LBMIE BIT(10) #define PCIE_RC_CONFIG_LCSR_LABIE BIT(11) @@ -477,6 +478,18 @@ static int rockchip_pcie_init_port(struct rockchip_pcie_port *port) return err; } + /* + * We need to read/write PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2 + * before enabling ASPM. Otherwise L1PwrOnSc and L1PwrOnVal isn't + * reliable which makes the controller in broken state when + * enabling ASPM. This is a controller's bug we need to work + * around. + */ + status = pcie_read(port, PCIE_RC_CONFIG_BASE + + PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2); + pcie_write(port, status, PCIE_RC_CONFIG_BASE + + PCIE_RC_CONFIG_L1_SUBSTATE_CTRL2); + /* Enable Gen1 training */ pcie_write(port, HIWORD_UPDATE(PCIE_CLIENT_LINK_TRAIN_ENABLE, -- 2.3.7