[PATCH 3/7] PCI: imx6: Fix waiting for link up
Marek Vasut
marex at denx.de
Tue Nov 26 16:10:44 EST 2013
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 <marex at denx.de>
Cc: Bjorn Helgaas <bhelgaas at google.com>
Cc: Frank Li <lznuaa at gmail.com>
Cc: Harro Haan <hrhaan at gmail.com>
Cc: Jingoo Han <jg1.han at samsung.com>
Cc: Mohit KUMAR <Mohit.KUMAR at st.com>
Cc: Pratyush Anand <pratyush.anand at st.com>
Cc: Richard Zhu <r65037 at freescale.com>
Cc: Sascha Hauer <s.hauer at pengutronix.de>
Cc: Sean Cross <xobs at kosagi.com>
Cc: Shawn Guo <shawn.guo at linaro.org>
Cc: Siva Reddy Kallam <siva.kallam at samsung.com>
Cc: Srikanth T Shivanand <ts.srikanth at samsung.com>
Cc: Tim Harvey <tharvey at gateworks.com>
Cc: Troy Kisky <troy.kisky at boundarydevices.com>
Cc: Yinghai Lu <yinghai at kernel.org>
---
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 52027ad..4d5be4e 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.
--
1.8.4.3
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