From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Osipenko Subject: Re: [PATCH V6 14/21] clk: tegra210: Add suspend and resume support Date: Mon, 22 Jul 2019 10:09:08 +0300 Message-ID: <5054f178-db27-9286-d123-3e2b2a885717@gmail.com> References: <1563738060-30213-1-git-send-email-skomatineni@nvidia.com> <1563738060-30213-15-git-send-email-skomatineni@nvidia.com> <88da46d2-b90d-f57e-7611-b8653b56bdf6@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Sowjanya Komatineni , thierry.reding@gmail.com, jonathanh@nvidia.com, tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com, linus.walleij@linaro.org, stefan@agner.ch, mark.rutland@arm.com Cc: pdeschrijver@nvidia.com, pgaikwad@nvidia.com, sboyd@kernel.org, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, jckuo@nvidia.com, josephl@nvidia.com, talho@nvidia.com, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, mperttunen@nvidia.com, spatra@nvidia.com, robh+dt@kernel.org, devicetree@vger.kernel.org List-Id: linux-tegra@vger.kernel.org 22.07.2019 9:52, Sowjanya Komatineni пишет: > > On 7/21/19 11:10 PM, Dmitry Osipenko wrote: >> 22.07.2019 1:45, Sowjanya Komatineni пишет: >>> On 7/21/19 2:38 PM, Dmitry Osipenko wrote: >>>> 21.07.2019 22:40, Sowjanya Komatineni пишет: >>>>> This patch adds support for clk: tegra210: suspend-resume. >>>>> >>>>> All the CAR controller settings are lost on suspend when core >>>>> power goes off. >>>>> >>>>> This patch has implementation for saving and restoring all PLLs >>>>> and clocks context during system suspend and resume to have the >>>>> clocks back to same state for normal operation. >>>>> >>>>> Acked-by: Thierry Reding >>>>> Signed-off-by: Sowjanya Komatineni >>>>> --- >>>>>    drivers/clk/tegra/clk-tegra210.c | 68 >>>>> ++++++++++++++++++++++++++++++++++++++-- >>>>>    drivers/clk/tegra/clk.c          | 14 +++++++++ >>>>>    drivers/clk/tegra/clk.h          |  1 + >>>>>    3 files changed, 80 insertions(+), 3 deletions(-) >>>>> >>>>> diff --git a/drivers/clk/tegra/clk-tegra210.c >>>>> b/drivers/clk/tegra/clk-tegra210.c >>>>> index 55a88c0824a5..68271873acc1 100644 >>>>> --- a/drivers/clk/tegra/clk-tegra210.c >>>>> +++ b/drivers/clk/tegra/clk-tegra210.c >>>>> @@ -9,6 +9,7 @@ >>>>>    #include >>>>>    #include >>>>>    #include >>>>> +#include >>>>>    #include >>>>>    #include >>>>>    #include >>>>> @@ -220,11 +221,15 @@ >>>>>    #define CLK_M_DIVISOR_SHIFT 2 >>>>>    #define CLK_M_DIVISOR_MASK 0x3 >>>>>    +#define CLK_MASK_ARM    0x44 >>>>> +#define MISC_CLK_ENB    0x48 >>>>> + >>>>>    #define RST_DFLL_DVCO 0x2f4 >>>>>    #define DVFS_DFLL_RESET_SHIFT 0 >>>>>      #define CLK_RST_CONTROLLER_RST_DEV_Y_SET 0x2a8 >>>>>    #define CLK_RST_CONTROLLER_RST_DEV_Y_CLR 0x2ac >>>>> +#define CPU_SOFTRST_CTRL 0x380 >>>>>      #define LVL2_CLK_GATE_OVRA 0xf8 >>>>>    #define LVL2_CLK_GATE_OVRC 0x3a0 >>>>> @@ -2825,6 +2830,7 @@ static int tegra210_enable_pllu(void) >>>>>        struct tegra_clk_pll_freq_table *fentry; >>>>>        struct tegra_clk_pll pllu; >>>>>        u32 reg; >>>>> +    int ret; >>>>>          for (fentry = pll_u_freq_table; fentry->input_rate; >>>>> fentry++) { >>>>>            if (fentry->input_rate == pll_ref_freq) >>>>> @@ -2853,9 +2859,8 @@ static int tegra210_enable_pllu(void) >>>>>        reg |= PLL_ENABLE; >>>>>        writel(reg, clk_base + PLLU_BASE); >>>>>    -    readl_relaxed_poll_timeout_atomic(clk_base + PLLU_BASE, reg, >>>>> -                      reg & PLL_BASE_LOCK, 2, 1000); >>>>> -    if (!(reg & PLL_BASE_LOCK)) { >>>>> +    ret = tegra210_wait_for_mask(&pllu, PLLU_BASE, PLL_BASE_LOCK); >>>>> +    if (ret) { >>>> Why this is needed? Was there a bug? >>>> >>> during resume pllu init is needed and to use same terga210_init_pllu, >>> poll_timeout_atomic can't be used as its ony for atomic context. >>> >>> So changed to use wait_for_mask which should work in both cases. >> Atomic variant could be used from any context, not sure what do you >> mean. The 'atomic' part only means that function won't cause scheduling >> and that's it. > > Sorry, replied incorrect. readx_poll_timeout_atomic uses ktime_get() and > during resume timekeeping suspend/resume happens later than clock > suspend/resume. So using tegra210_wait_for_mask. > > both timekeeping and clk-tegra210 drivers are registered as syscore but > not ordered. Okay, thank you for the clarification. [snip]