On Tuesday 21 November 2017 03:00 AM, Bjorn Helgaas wrote:
s/PCI: tegra: fixups to avoid unnecessary .../
/PCI: tegra: <Capitalized verb> .../
I'll take care of this in next patch
On Sun, Nov 12, 2017 at 06:47:53PM +0530, Vidya Sagar wrote:
sets CLKREQ asserted delay to a higher value to avoid
unnecessary wake up from L1.2_ENTRY state for Tegra210
"L1.2.Entry" to match the spec sec 5.5.3.1 (at least I assume that's
what this refers to).
I'll take care of this in next patch
Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
---
V2:
* no change in this patch
V3:
* no change in this patch
drivers/pci/host/pci-tegra.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index 6d68f49f152e..29ee4bb0b7c6 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -204,6 +204,8 @@
#define RP_L1_PM_SUBSTATES_1_CTL 0xC04
#define RP_L1_PM_SUBSTATES_1_CTL_PWR_OFF_DLY_MASK 0x1FFF
#define RP_L1_PM_SUBSTATES_1_CTL_PWR_OFF_DLY 0x26
+#define RP_L1SS_1_CTL_CLKREQ_ASSERTED_DLY_MASK (0x1FF << 13)
+#define RP_L1SS_1_CTL_CLKREQ_ASSERTED_DLY (0x27 << 13)
#define RP_L1_PM_SUBSTATES_2_CTL 0xC08
#define RP_L1_PM_SUBSTATES_2_CTL_T_L1_2_DLY_MASK 0x1FFF
@@ -350,6 +352,7 @@ struct tegra_pcie_soc {
bool program_deskew_time;
bool updateFC_threshold;
bool has_aspm_l1ss;
+ bool l1ss_rp_wake_fixup;
};
static inline struct tegra_msi *to_tegra_msi(struct msi_controller *chip)
@@ -2290,6 +2293,16 @@ static void tegra_pcie_apply_sw_fixup(struct tegra_pcie_port *port)
(7 << RP_L1_PM_SUBSTATES_CTL_T_PWRN_VAL_SHIFT);
writel(value, port->base + RP_L1_PM_SUBSTATES_CTL);
+ if (soc->l1ss_rp_wake_fixup) {
+ /* Set CLKREQ asserted delay greater than Power_Off
+ * time (2us) to avoid RP wakeup in L1.2_ENTRY
+ */
Use standard multi-line comment formatting (and "L1.2.Entry" as above).
I'll take care of it in next patch
I assume "CLKREQ asserted delay" is a Tegra-internal thing, since it
doesn't obviously correspond to a timing parameter in the spec.
Yes. Its Tegra's internal thing
And I assume it doesn't depend on any of the OS-writable things in the
L1 PM Substates control registers, since this fixup isn't executed
during config writes to those registers?
Yes. It doesn't depend on any OS-writable value in L1 PM Substates
control registers.
Its a one time programmable value to be written before root port's LTSSM
starts.
Does this depend on any circuit details outside of Tegra, i.e., should
it be described via DT?
Nope. It doesn't depend on any external (to Tegra) circuitry.
+ value = readl(port->base + RP_L1_PM_SUBSTATES_1_CTL);
+ value &= ~RP_L1SS_1_CTL_CLKREQ_ASSERTED_DLY_MASK;
+ value |= RP_L1SS_1_CTL_CLKREQ_ASSERTED_DLY;
+ writel(value, port->base + RP_L1_PM_SUBSTATES_1_CTL);
+ }
+
/* Following is based on clk_m being 19.2 MHz */
value = readl(port->base + RP_L1_PM_SUBSTATES_1_CTL);
value &= ~RP_L1_PM_SUBSTATES_1_CTL_PWR_OFF_DLY_MASK;
@@ -2446,6 +2459,7 @@ static const struct tegra_pcie_soc tegra20_pcie = {
.program_deskew_time = false,
.updateFC_threshold = false,
.has_aspm_l1ss = false,
+ .l1ss_rp_wake_fixup = false,
};
static const struct tegra_pcie_soc tegra30_pcie = {
@@ -2468,6 +2482,7 @@ static const struct tegra_pcie_soc tegra30_pcie = {
.program_deskew_time = false,
.updateFC_threshold = false,
.has_aspm_l1ss = false,
+ .l1ss_rp_wake_fixup = false,
};
static const struct tegra_pcie_soc tegra124_pcie = {
@@ -2489,6 +2504,7 @@ static const struct tegra_pcie_soc tegra124_pcie = {
.program_deskew_time = false,
.updateFC_threshold = false,
.has_aspm_l1ss = false,
+ .l1ss_rp_wake_fixup = false,
};
static const struct tegra_pcie_soc tegra210_pcie = {
@@ -2518,6 +2534,7 @@ static const struct tegra_pcie_soc tegra210_pcie = {
.program_deskew_time = true,
.updateFC_threshold = true,
.has_aspm_l1ss = true,
+ .l1ss_rp_wake_fixup = true,
};
static const struct tegra_pcie_soc tegra186_pcie = {
@@ -2540,6 +2557,7 @@ static const struct tegra_pcie_soc tegra186_pcie = {
.program_deskew_time = false,
.updateFC_threshold = false,
.has_aspm_l1ss = true,
+ .l1ss_rp_wake_fixup = false,
};
static const struct of_device_id tegra_pcie_of_match[] = {
--
2.7.4
