From e47c4d7014d26c33aaa7522f06b4db4581d54703 Mon Sep 17 00:00:00 2001 From: Luka Perkov Date: Mon, 11 Aug 2014 20:35:04 +0000 Subject: [PATCH] imx6: kernel: fix occasional link failure Signed-off-by: Tim Harvey SVN-Revision: 42145 --- .../0060-pci_imx6_fix-link-failure.patch | 38 +++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 target/linux/imx6/patches-3.14/0060-pci_imx6_fix-link-failure.patch diff --git a/target/linux/imx6/patches-3.14/0060-pci_imx6_fix-link-failure.patch b/target/linux/imx6/patches-3.14/0060-pci_imx6_fix-link-failure.patch new file mode 100644 index 000000000000..e416d8332db4 --- /dev/null +++ b/target/linux/imx6/patches-3.14/0060-pci_imx6_fix-link-failure.patch @@ -0,0 +1,38 @@ +PCI: imx6: fix occasional link failure + +According to the IMX6 reference manuals, REF_SSP_EN (Reference clock enable +for SS function) must remain deasserted until the reference clock is running +at the appropriate frequency. + +Without this patch we find a high link failure rate (>5%) on certain +IMX6 boards at various temperatures. + +Signed-off-by: Tim Harvey + +--- a/drivers/pci/host/pci-imx6.c ++++ b/drivers/pci/host/pci-imx6.c +@@ -262,11 +262,6 @@ static int imx6_pcie_deassert_core_reset + if (gpio_is_valid(imx6_pcie->power_on_gpio)) + gpio_set_value(imx6_pcie->power_on_gpio, 1); + +- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, +- IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); +- regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, +- IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16); +- + ret = clk_prepare_enable(imx6_pcie->sata_ref_100m); + if (ret) { + dev_err(pp->dev, "unable to enable sata_ref_100m\n"); +@@ -294,6 +289,12 @@ static int imx6_pcie_deassert_core_reset + /* allow the clocks to stabilize */ + usleep_range(200, 500); + ++ /* power up core phy and enable ref clock */ ++ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, ++ IMX6Q_GPR1_PCIE_TEST_PD, 0 << 18); ++ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, ++ IMX6Q_GPR1_PCIE_REF_CLK_EN, 1 << 16); ++ + /* Some boards don't have PCIe reset GPIO. */ + if (gpio_is_valid(imx6_pcie->reset_gpio)) { + gpio_set_value(imx6_pcie->reset_gpio, 0); -- 2.30.2