[PATCH v6 07/12] ARM: tegra: Don't enable PLLX while resuming from LP1 on Tegra30

From: Dmitry Osipenko
Date: Wed Dec 18 2019 - 15:22:33 EST


PLLX may be kept disabled if cpufreq driver selects some other clock for
CPU. In that case PLLX will be disabled later in the resume path by the
CLK driver, which also can enable PLLX if necessary by itself. Thus there
is no need to enable PLLX early during resume. Tegra114/124 CLK drivers do
not manage PLLX on resume and thus they are left untouched by this patch.

Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
arch/arm/mach-tegra/sleep-tegra30.S | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-tegra/sleep-tegra30.S b/arch/arm/mach-tegra/sleep-tegra30.S
index 9a20c93abe48..4f073869b8ac 100644
--- a/arch/arm/mach-tegra/sleep-tegra30.S
+++ b/arch/arm/mach-tegra/sleep-tegra30.S
@@ -358,7 +358,6 @@ _no_pll_iddq_exit:

pll_enable r1, r0, CLK_RESET_PLLM_BASE, CLK_RESET_PLLM_MISC
pll_enable r1, r0, CLK_RESET_PLLC_BASE, CLK_RESET_PLLC_MISC
- pll_enable r1, r0, CLK_RESET_PLLX_BASE, CLK_RESET_PLLX_MISC

_pll_m_c_x_done:
pll_enable r1, r0, CLK_RESET_PLLP_BASE, CLK_RESET_PLLP_MISC
@@ -368,8 +367,18 @@ _pll_m_c_x_done:
pll_locked r1, r0, CLK_RESET_PLLP_BASE
pll_locked r1, r0, CLK_RESET_PLLA_BASE
pll_locked r1, r0, CLK_RESET_PLLC_BASE
+
+ /*
+ * CPUFreq driver could select other PLL for CPU. PLLX will be
+ * enabled by the Tegra30 CLK driver on an as-needed basis, see
+ * tegra30_cpu_clock_resume().
+ */
+ cmp r10, #TEGRA30
+ beq _pll_m_c_x_locked
+
pll_locked r1, r0, CLK_RESET_PLLX_BASE

+_pll_m_c_x_locked:
mov32 r7, TEGRA_TMRUS_BASE
ldr r1, [r7]
add r1, r1, #LOCK_DELAY
--
2.24.0