From b2634cd0d26d2431f065e06e30069ce11a081755 Mon Sep 17 00:00:00 2001 From: Manikanta Maddireddy Date: Tue, 18 Jun 2019 23:31:52 +0530 Subject: [PATCH] PCI: tegra: Increase the deskew retry time Sometimes link speed change from Gen2 to Gen1 fails due to instability in deskew logic on lane-0 in Tegra210. Increase the deskew retry time to resolve this issue. Signed-off-by: Manikanta Maddireddy Signed-off-by: Lorenzo Pieralisi Acked-by: Thierry Reding --- drivers/pci/controller/pci-tegra.c | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c index 56648b2fa0ee0d..609edcb45f4738 100644 --- a/drivers/pci/controller/pci-tegra.c +++ b/drivers/pci/controller/pci-tegra.c @@ -209,6 +209,10 @@ #define RP_VEND_XP_OPPORTUNISTIC_ACK (1 << 27) #define RP_VEND_XP_OPPORTUNISTIC_UPDATEFC (1 << 28) +#define RP_VEND_CTL0 0x00000f44 +#define RP_VEND_CTL0_DSK_RST_PULSE_WIDTH_MASK (0xf << 12) +#define RP_VEND_CTL0_DSK_RST_PULSE_WIDTH (0x9 << 12) + #define RP_VEND_CTL1 0x00000f48 #define RP_VEND_CTL1_ERPT (1 << 13) @@ -305,6 +309,7 @@ struct tegra_pcie_soc { bool force_pca_enable; bool program_uphy; bool update_clamp_threshold; + bool program_deskew_time; struct { struct { u32 rp_ectl_2_r1; @@ -620,6 +625,24 @@ static void tegra_pcie_program_ectl_settings(struct tegra_pcie_port *port) writel(value, port->base + RP_ECTL_6_R2); } +static void tegra_pcie_apply_sw_fixup(struct tegra_pcie_port *port) +{ + const struct tegra_pcie_soc *soc = port->pcie->soc; + u32 value; + + /* + * Sometimes link speed change from Gen2 to Gen1 fails due to + * instability in deskew logic on lane-0. Increase the deskew + * retry time to resolve this issue. + */ + if (soc->program_deskew_time) { + value = readl(port->base + RP_VEND_CTL0); + value &= ~RP_VEND_CTL0_DSK_RST_PULSE_WIDTH_MASK; + value |= RP_VEND_CTL0_DSK_RST_PULSE_WIDTH; + writel(value, port->base + RP_VEND_CTL0); + } +} + static void tegra_pcie_port_enable(struct tegra_pcie_port *port) { unsigned long ctrl = tegra_pcie_port_get_pex_ctrl(port); @@ -649,6 +672,8 @@ static void tegra_pcie_port_enable(struct tegra_pcie_port *port) if (soc->ectl.enable) tegra_pcie_program_ectl_settings(port); + + tegra_pcie_apply_sw_fixup(port); } static void tegra_pcie_port_disable(struct tegra_pcie_port *port) @@ -2375,6 +2400,7 @@ static const struct tegra_pcie_soc tegra20_pcie = { .force_pca_enable = false, .program_uphy = true, .update_clamp_threshold = false, + .program_deskew_time = false, .ectl.enable = false, }; @@ -2400,6 +2426,7 @@ static const struct tegra_pcie_soc tegra30_pcie = { .force_pca_enable = false, .program_uphy = true, .update_clamp_threshold = false, + .program_deskew_time = false, .ectl.enable = false, }; @@ -2418,6 +2445,7 @@ static const struct tegra_pcie_soc tegra124_pcie = { .force_pca_enable = false, .program_uphy = true, .update_clamp_threshold = true, + .program_deskew_time = false, .ectl.enable = false, }; @@ -2436,6 +2464,7 @@ static const struct tegra_pcie_soc tegra210_pcie = { .force_pca_enable = true, .program_uphy = true, .update_clamp_threshold = true, + .program_deskew_time = true, .ectl = { .regs = { .rp_ectl_2_r1 = 0x0000000f, @@ -2473,6 +2502,7 @@ static const struct tegra_pcie_soc tegra186_pcie = { .force_pca_enable = false, .program_uphy = false, .update_clamp_threshold = false, + .program_deskew_time = false, .ectl.enable = false, };