diff options
Diffstat (limited to 'target/linux/imx6/patches-3.14/0055-pci_imx6_fix-boot-hang-when-link-already-enabled.patch')
| -rw-r--r-- | target/linux/imx6/patches-3.14/0055-pci_imx6_fix-boot-hang-when-link-already-enabled.patch | 86 |
1 files changed, 0 insertions, 86 deletions
diff --git a/target/linux/imx6/patches-3.14/0055-pci_imx6_fix-boot-hang-when-link-already-enabled.patch b/target/linux/imx6/patches-3.14/0055-pci_imx6_fix-boot-hang-when-link-already-enabled.patch deleted file mode 100644 index bae5a1f..0000000 --- a/target/linux/imx6/patches-3.14/0055-pci_imx6_fix-boot-hang-when-link-already-enabled.patch +++ /dev/null @@ -1,86 +0,0 @@ -This fixes a boot hang observed when the bootloader -already enabled the PCIe link for it's own use. The -fundamental problem is that Freescale forgot to wire -up the core reset, so software doesn't have a sane way -to get the core into a defined state. - -According to the DW PCIe core reference manual configuration -of the core may only happen when the LTSSM is disabled, so -this is one of the first things we need to do. Apparently -this isn't safe to do when the LTSSM is in any other state -than "detect" as we observe an instant machine hang when -trying to do so while the link is already up. - -As a workaround force LTSSM into detect state right before -hitting the disable switch. - -Reported-by: Fabio Estevam <fabio.estevam <at> freescale.com> -Signed-off-by: Lucas Stach <l.stach <at> pengutronix.de> -Acked-by: Tim Harvey <tharvey <at> gateworks.com> ---- a/drivers/pci/host/pci-imx6.c -+++ b/drivers/pci/host/pci-imx6.c -@@ -52,6 +52,9 @@ struct imx6_pcie { - - /* PCIe Port Logic registers (memory-mapped) */ - #define PL_OFFSET 0x700 -+#define PCIE_PL_PFLR (PL_OFFSET + 0x08) -+#define PCIE_PL_PFLR_LINK_STATE_MASK (0x3f << 16) -+#define PCIE_PL_PFLR_FORCE_LINK (1 << 15) - #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) -@@ -217,6 +220,31 @@ static int imx6q_pcie_abort_handler(unsi - static int imx6_pcie_assert_core_reset(struct pcie_port *pp) - { - struct imx6_pcie *imx6_pcie = to_imx6_pcie(pp); -+ u32 val, gpr1, gpr12; -+ -+ /* -+ * If the bootloader already enabled the link we need some special -+ * handling to get the core back into a state where it is safe to -+ * touch it for configuration. As there is no dedicated reset signal -+ * wired up for MX6QDL, we need to manually force LTSSM into "detect" -+ * state before completely disabling LTSSM, which is a prerequisite -+ * for core configuration. -+ * If both LTSSM_ENABLE and REF_SSP_ENABLE are active we have a strong -+ * indication that the bootloader activated the link. -+ */ -+ regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, &gpr1); -+ regmap_read(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, &gpr12); -+ -+ if ((gpr1 & IMX6Q_GPR1_PCIE_REF_CLK_EN) && -+ (gpr12 & IMX6Q_GPR12_PCIE_CTL_2)) { -+ val = readl(pp->dbi_base + PCIE_PL_PFLR); -+ val &= ~PCIE_PL_PFLR_LINK_STATE_MASK; -+ val |= PCIE_PL_PFLR_FORCE_LINK; -+ writel(val, pp->dbi_base + PCIE_PL_PFLR); -+ -+ regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR12, -+ IMX6Q_GPR12_PCIE_CTL_2, 0 << 10); -+ } - - regmap_update_bits(imx6_pcie->iomuxc_gpr, IOMUXC_GPR1, - IMX6Q_GPR1_PCIE_TEST_PD, 1 << 18); -@@ -627,6 +655,14 @@ static int __init imx6_pcie_probe(struct - return 0; - } - -+static void imx6_pcie_shutdown(struct platform_device *pdev) -+{ -+ struct imx6_pcie *imx6_pcie = platform_get_drvdata(pdev); -+ -+ /* bring down link, so bootloader gets clean state in case of reboot */ -+ imx6_pcie_assert_core_reset(&imx6_pcie->pp); -+} -+ - static const struct of_device_id imx6_pcie_of_match[] = { - { .compatible = "fsl,imx6q-pcie", }, - {}, -@@ -639,6 +675,7 @@ static struct platform_driver imx6_pcie_ - .owner = THIS_MODULE, - .of_match_table = imx6_pcie_of_match, - }, -+ .shutdown = imx6_pcie_shutdown, - }; - - /* Freescale PCIe driver does not allow module unload */ |