From 7f9f40c01cce0c0e0ced34af2a2fd8353cc606c3 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Thu, 12 Dec 2013 22:49:59 +0100 Subject: [PATCH] PCI: imx6: Report "link up" only after link training completes While waiting for the PHY to report the PCIe link is up, we might hit a situation where the link training is still in progress, while the PHY already reports the link is up. Add additional check for this condition. Signed-off-by: Marek Vasut Signed-off-by: Bjorn Helgaas Acked-by: Shawn Guo Cc: Frank Li Cc: Harro Haan Cc: Jingoo Han Cc: Mohit KUMAR Cc: Pratyush Anand Cc: Richard Zhu Cc: Sascha Hauer Cc: Sean Cross Cc: Siva Reddy Kallam Cc: Srikanth T Shivanand Cc: Tim Harvey Cc: Troy Kisky Cc: Yinghai Lu --- drivers/pci/host/pci-imx6.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/pci/host/pci-imx6.c b/drivers/pci/host/pci-imx6.c index 1176bddee1cc..5634a33ea642 100644 --- a/drivers/pci/host/pci-imx6.c +++ b/drivers/pci/host/pci-imx6.c @@ -48,6 +48,8 @@ struct imx6_pcie { #define PL_OFFSET 0x700 #define PCIE_PHY_DEBUG_R0 (PL_OFFSET + 0x28) #define PCIE_PHY_DEBUG_R1 (PL_OFFSET + 0x2c) +#define PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING (1 << 29) +#define PCIE_PHY_DEBUG_R1_XMLH_LINK_UP (1 << 4) #define PCIE_PHY_CTRL (PL_OFFSET + 0x114) #define PCIE_PHY_CTRL_DATA_LOC 0 @@ -338,10 +340,17 @@ static int imx6_pcie_link_up(struct pcie_port *pp) { u32 rc, ltssm, rx_valid, temp; - /* link is debug bit 36, debug register 1 starts at bit 32 */ - rc = readl(pp->dbi_base + PCIE_PHY_DEBUG_R1) & (0x1 << (36 - 32)); - if (rc) - return -EAGAIN; + /* + * Test if the PHY reports that the link is up and also that + * the link training finished. It might happen that the PHY + * reports the link is already up, but the link training bit + * is still set, so make sure to check the training is done + * as well here. + */ + rc = readl(pp->dbi_base + PCIE_PHY_DEBUG_R1); + if ((rc & PCIE_PHY_DEBUG_R1_XMLH_LINK_UP) && + !(rc & PCIE_PHY_DEBUG_R1_XMLH_LINK_IN_TRAINING)) + return 1; /* * From L0, initiate MAC entry to gen2 if EP/RC supports gen2. -- 2.30.2