On 13-Dec-17 7:38 PM, Lorenzo Pieralisi wrote:
> 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 <mmaddireddy@xxxxxxxxxx>
>>>> ---
>>>> 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
>
New sequence with this patch will be
tegra_pcie_enable_controller() -> tegra_pcie_request_resources() -> tegra_pcie_enable_ports()
->goto put_resources on fail -> reset_control_deassert(pcie->pcie_xrst);
Since pcie_xrst deassert happens after tegra_pcie_request_resources(), there is no need to assert pcie_xrst on put_resource failure.
>>>> 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
>>>>
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