From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Pieralisi Subject: Re: [PATCH V3 01/12] PCI: tegra: Start LTSSM after programming root port Date: Wed, 13 Dec 2017 14:08:57 +0000 Message-ID: <20171213140848.GA1736@red-moon> References: <1509371843-22931-1-git-send-email-mmaddireddy@nvidia.com> <1509371843-22931-2-git-send-email-mmaddireddy@nvidia.com> <20171212113248.GA30799@e107981-ln.cambridge.arm.com> <7d3396dc-b133-5645-24da-a20fd9db6286@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <7d3396dc-b133-5645-24da-a20fd9db6286-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Manikanta Maddireddy Cc: thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, vidyas-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, mperttunen-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kthota-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org List-Id: linux-tegra@vger.kernel.org On Wed, Dec 13, 2017 at 05:20:39PM +0530, Manikanta Maddireddy wrote: > > > On 12-Dec-17 5:02 PM, Lorenzo Pieralisi wrote: > > On Mon, Oct 30, 2017 at 07:27:12PM +0530, 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 > >> --- > >> V3: > >> * no change in this patch > >> 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); > > > > This does not look like it is part of the reset de-assertion code move. > > > > tegra_pcie_enable_controller() -> tegra_pcie_enable_ports() > > > > in other words, why are you removing it ? > > > > Lorenzo > > Hi Lorenzo, > > Host driver should start LTSSM after programming all controller registers. > In tegra_pcie_enable_controller() bunch of AFI module programming is done and > I am adding PCIe register programming in this series. > So I moved deasserting of pcie_xrst(which starts LTSSM) to tegra_pcie_enable_ports(), > which is right after sending RST pulse(tegra_pcie_port_reset()) to endpoint. I asked why you removed the reset assertion in tegra_pcie_power_off(), it is not clear to me. You still call tegra_pcie_power_off() in the tegra_pcie_probe() error path and I see no reason why the reset assertion - called through: tegra_pcie_put_resources() -> tegra_pcie_power_of() is removed, if it was needed previously. Lorenzo > >> 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; > >> > >> -- > >> 2.1.4 > >>