| Message ID | 1509337143-25963-2-git-send-email-mmaddireddy@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On 30.10.2017 06:18, Manikanta Maddireddy wrote: > This patch ensures that LTSSM is started (by deasserting pcie_xrst) only > after all the required root port register programming is completed. > > Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com> > --- > V2: > * no change in this patch > > drivers/pci/host/pci-tegra.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c > index 96e8038c3019..b41c60c7414c 100644 > --- a/drivers/pci/host/pci-tegra.c > +++ b/drivers/pci/host/pci-tegra.c > @@ -1024,9 +1024,6 @@ static int tegra_pcie_enable_controller(struct tegra_pcie *pcie) > } > } > > - /* take the PCIe interface module out of reset */ > - reset_control_deassert(pcie->pcie_xrst); > - > /* finally enable PCIe */ > value = afi_readl(pcie, AFI_CONFIGURATION); > value |= AFI_CONFIGURATION_EN_FPCI; > @@ -1065,7 +1062,6 @@ static void tegra_pcie_power_off(struct tegra_pcie *pcie) > dev_err(dev, "failed to power off PHY(s): %d\n", err); > } > > - reset_control_assert(pcie->pcie_xrst); Why is this change being made? Is there a reason we cannot leave this reset asserted when the controller is powered off? > reset_control_assert(pcie->afi_rst); > reset_control_assert(pcie->pex_rst); > > @@ -2116,7 +2112,12 @@ static void tegra_pcie_enable_ports(struct tegra_pcie *pcie) > port->index, port->lanes); > > tegra_pcie_port_enable(port); > + } > > + /* take the PCIe interface module out of reset */ > + reset_control_deassert(pcie->pcie_xrst); > + > + list_for_each_entry_safe(port, tmp, &pcie->ports, list) { > if (tegra_pcie_port_check_link(port)) > continue; > >
On 30-Oct-17 2:38 PM, Mikko Perttunen wrote: > On 30.10.2017 06:18, Manikanta Maddireddy wrote: >> This patch ensures that LTSSM is started (by deasserting pcie_xrst) only >> after all the required root port register programming is completed. >> >> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com> >> --- >> V2: >> * no change in this patch >> >> drivers/pci/host/pci-tegra.c | 9 +++++---- >> 1 file changed, 5 insertions(+), 4 deletions(-) >> >> diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c >> index 96e8038c3019..b41c60c7414c 100644 >> --- a/drivers/pci/host/pci-tegra.c >> +++ b/drivers/pci/host/pci-tegra.c >> @@ -1024,9 +1024,6 @@ static int tegra_pcie_enable_controller(struct tegra_pcie *pcie) >> } >> } >> >> - /* take the PCIe interface module out of reset */ >> - reset_control_deassert(pcie->pcie_xrst); >> - >> /* finally enable PCIe */ >> value = afi_readl(pcie, AFI_CONFIGURATION); >> value |= AFI_CONFIGURATION_EN_FPCI; >> @@ -1065,7 +1062,6 @@ static void tegra_pcie_power_off(struct tegra_pcie *pcie) >> dev_err(dev, "failed to power off PHY(s): %d\n", err); >> } >> >> - reset_control_assert(pcie->pcie_xrst); > > Why is this change being made? Is there a reason we cannot leave this reset asserted when the controller is powered off? In this change I moved deassert pcie_xrst to tegra_pcie_enable_ports. tegra_pcie_power_off() will not come into picture after deasserting pcie xrst. So this asserting pcie xrst redundant now. > >> reset_control_assert(pcie->afi_rst); >> reset_control_assert(pcie->pex_rst); >> >> @@ -2116,7 +2112,12 @@ static void tegra_pcie_enable_ports(struct tegra_pcie *pcie) >> port->index, port->lanes); >> >> tegra_pcie_port_enable(port); >> + } >> >> + /* take the PCIe interface module out of reset */ >> + reset_control_deassert(pcie->pcie_xrst); >> + >> + list_for_each_entry_safe(port, tmp, &pcie->ports, list) { >> if (tegra_pcie_port_check_link(port)) >> continue; >> >>
diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c index 96e8038c3019..b41c60c7414c 100644 --- a/drivers/pci/host/pci-tegra.c +++ b/drivers/pci/host/pci-tegra.c @@ -1024,9 +1024,6 @@ static int tegra_pcie_enable_controller(struct tegra_pcie *pcie) } } - /* take the PCIe interface module out of reset */ - reset_control_deassert(pcie->pcie_xrst); - /* finally enable PCIe */ value = afi_readl(pcie, AFI_CONFIGURATION); value |= AFI_CONFIGURATION_EN_FPCI; @@ -1065,7 +1062,6 @@ static void tegra_pcie_power_off(struct tegra_pcie *pcie) dev_err(dev, "failed to power off PHY(s): %d\n", err); } - reset_control_assert(pcie->pcie_xrst); reset_control_assert(pcie->afi_rst); reset_control_assert(pcie->pex_rst); @@ -2116,7 +2112,12 @@ static void tegra_pcie_enable_ports(struct tegra_pcie *pcie) port->index, port->lanes); tegra_pcie_port_enable(port); + } + /* take the PCIe interface module out of reset */ + reset_control_deassert(pcie->pcie_xrst); + + list_for_each_entry_safe(port, tmp, &pcie->ports, list) { if (tegra_pcie_port_check_link(port)) continue;
This patch ensures that LTSSM is started (by deasserting pcie_xrst) only after all the required root port register programming is completed. Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com> --- V2: * no change in this patch drivers/pci/host/pci-tegra.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)