[PATCH v7 07/12] ARM: tegra: Don't enable PLLX while resuming from LP1 on Tegra30

From: Dmitry Osipenko
Date: Wed Feb 12 2020 - 18:46:43 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.

Acked-by: Peter De Schrijver <pdeschrijver@xxxxxxxxxx>
Tested-by: Peter Geis <pgwipeout@xxxxxxxxx>
Tested-by: Marcel Ziswiler <marcel@xxxxxxxxxxxx>
Tested-by: Jasper Korten <jja2000@xxxxxxxxx>
Tested-by: David Heidelberg <david@xxxxxxx>
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
arch/arm/mach-tegra/sleep-tegra30.S | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-tegra/sleep-tegra30.S b/arch/arm/mach-tegra/sleep-tegra30.S
index b897d4a433b3..c3946dbd0240 100644
--- a/arch/arm/mach-tegra/sleep-tegra30.S
+++ b/arch/arm/mach-tegra/sleep-tegra30.S
@@ -361,7 +361,6 @@ _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
@@ -371,12 +370,18 @@ _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
- pll_locked r1, r0, CLK_RESET_PLLX_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().
+ */
tegra_get_soc_id TEGRA_APB_MISC_BASE, r1
cmp r1, #TEGRA30
beq 1f

+ pll_locked r1, r0, CLK_RESET_PLLX_BASE
+
ldr r1, [r0, #CLK_RESET_PLLP_BASE]
bic r1, r1, #(1<<31) @ disable PllP bypass
str r1, [r0, #CLK_RESET_PLLP_BASE]
--
2.24.0