* [PATCH] clk: tegra: Use readl_relaxed_poll_timeout_atomic in tegra210_clock_init
@ 2017-09-15 1:36 Nicolin Chen
2017-09-15 9:31 ` Peter De Schrijver
0 siblings, 1 reply; 3+ messages in thread
From: Nicolin Chen @ 2017-09-15 1:36 UTC (permalink / raw)
To: pdeschrijver
Cc: linux-kernel, linux-tegra, linux-clk, jonathanh, thierry.reding,
sboyd, mturquette, pgaikwad
Below is the call trace of tegra210_init_pllu() function:
start_kernel()
-> time_init()
--> of_clk_init()
---> tegra210_clock_init()
----> tegra210_pll_init()
-----> tegra210_init_pllu()
Because the preemtion is disabled in the start_kernel before calling
time_init, tegra210_init_pllu is actually in an atomic context while
it includes a readl_relaxed_poll_timeout that might sleep.
So this patch just changes this readl_relaxed_poll_timeout() to its
atomic version.
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
---
drivers/clk/tegra/clk-tegra210.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
index 0b9789a..ea695c4 100644
--- a/drivers/clk/tegra/clk-tegra210.c
+++ b/drivers/clk/tegra/clk-tegra210.c
@@ -2587,8 +2587,8 @@ static int tegra210_enable_pllu(void)
reg |= PLL_ENABLE;
writel(reg, clk_base + PLLU_BASE);
- readl_relaxed_poll_timeout(clk_base + PLLU_BASE, reg,
- reg & PLL_BASE_LOCK, 2, 1000);
+ readl_relaxed_poll_timeout_atomic(clk_base + PLLU_BASE, reg,
+ reg & PLL_BASE_LOCK, 2, 1000);
if (!(reg & PLL_BASE_LOCK)) {
pr_err("Timed out waiting for PLL_U to lock\n");
return -ETIMEDOUT;
--
2.1.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] clk: tegra: Use readl_relaxed_poll_timeout_atomic in tegra210_clock_init
2017-09-15 1:36 [PATCH] clk: tegra: Use readl_relaxed_poll_timeout_atomic in tegra210_clock_init Nicolin Chen
@ 2017-09-15 9:31 ` Peter De Schrijver
2017-09-16 5:26 ` Nicolin Chen
0 siblings, 1 reply; 3+ messages in thread
From: Peter De Schrijver @ 2017-09-15 9:31 UTC (permalink / raw)
To: Nicolin Chen
Cc: linux-kernel, linux-tegra, linux-clk, jonathanh, thierry.reding,
sboyd, mturquette, pgaikwad
Apart from the typo in the commit message (preemption rather than preemtion):
Acked-By: Peter De Schrijver <pdeschrijver@nvidia.com>
On Thu, Sep 14, 2017 at 06:36:14PM -0700, Nicolin Chen wrote:
> Below is the call trace of tegra210_init_pllu() function:
> start_kernel()
> -> time_init()
> --> of_clk_init()
> ---> tegra210_clock_init()
> ----> tegra210_pll_init()
> -----> tegra210_init_pllu()
>
> Because the preemtion is disabled in the start_kernel before calling
> time_init, tegra210_init_pllu is actually in an atomic context while
> it includes a readl_relaxed_poll_timeout that might sleep.
>
> So this patch just changes this readl_relaxed_poll_timeout() to its
> atomic version.
>
> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
> ---
> drivers/clk/tegra/clk-tegra210.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
> index 0b9789a..ea695c4 100644
> --- a/drivers/clk/tegra/clk-tegra210.c
> +++ b/drivers/clk/tegra/clk-tegra210.c
> @@ -2587,8 +2587,8 @@ static int tegra210_enable_pllu(void)
> reg |= PLL_ENABLE;
> writel(reg, clk_base + PLLU_BASE);
>
> - readl_relaxed_poll_timeout(clk_base + PLLU_BASE, reg,
> - reg & PLL_BASE_LOCK, 2, 1000);
> + readl_relaxed_poll_timeout_atomic(clk_base + PLLU_BASE, reg,
> + reg & PLL_BASE_LOCK, 2, 1000);
> if (!(reg & PLL_BASE_LOCK)) {
> pr_err("Timed out waiting for PLL_U to lock\n");
> return -ETIMEDOUT;
> --
> 2.1.4
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] clk: tegra: Use readl_relaxed_poll_timeout_atomic in tegra210_clock_init
2017-09-15 9:31 ` Peter De Schrijver
@ 2017-09-16 5:26 ` Nicolin Chen
0 siblings, 0 replies; 3+ messages in thread
From: Nicolin Chen @ 2017-09-16 5:26 UTC (permalink / raw)
To: Peter De Schrijver
Cc: linux-kernel, linux-tegra, linux-clk, jonathanh, thierry.reding,
sboyd, mturquette, pgaikwad
On Fri, Sep 15, 2017 at 12:31:45PM +0300, Peter De Schrijver wrote:
> Apart from the typo in the commit message (preemption rather than preemtion):
Sent a v2 to correct it. And included your Acked-by.
Thanks
>
> Acked-By: Peter De Schrijver <pdeschrijver@nvidia.com>
>
> On Thu, Sep 14, 2017 at 06:36:14PM -0700, Nicolin Chen wrote:
> > Below is the call trace of tegra210_init_pllu() function:
> > start_kernel()
> > -> time_init()
> > --> of_clk_init()
> > ---> tegra210_clock_init()
> > ----> tegra210_pll_init()
> > -----> tegra210_init_pllu()
> >
> > Because the preemtion is disabled in the start_kernel before calling
> > time_init, tegra210_init_pllu is actually in an atomic context while
> > it includes a readl_relaxed_poll_timeout that might sleep.
> >
> > So this patch just changes this readl_relaxed_poll_timeout() to its
> > atomic version.
> >
> > Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
> > ---
> > drivers/clk/tegra/clk-tegra210.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/clk/tegra/clk-tegra210.c b/drivers/clk/tegra/clk-tegra210.c
> > index 0b9789a..ea695c4 100644
> > --- a/drivers/clk/tegra/clk-tegra210.c
> > +++ b/drivers/clk/tegra/clk-tegra210.c
> > @@ -2587,8 +2587,8 @@ static int tegra210_enable_pllu(void)
> > reg |= PLL_ENABLE;
> > writel(reg, clk_base + PLLU_BASE);
> >
> > - readl_relaxed_poll_timeout(clk_base + PLLU_BASE, reg,
> > - reg & PLL_BASE_LOCK, 2, 1000);
> > + readl_relaxed_poll_timeout_atomic(clk_base + PLLU_BASE, reg,
> > + reg & PLL_BASE_LOCK, 2, 1000);
> > if (!(reg & PLL_BASE_LOCK)) {
> > pr_err("Timed out waiting for PLL_U to lock\n");
> > return -ETIMEDOUT;
> > --
> > 2.1.4
> >
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-09-15 1:36 [PATCH] clk: tegra: Use readl_relaxed_poll_timeout_atomic in tegra210_clock_init Nicolin Chen
2017-09-15 9:31 ` Peter De Schrijver
2017-09-16 5:26 ` Nicolin Chen
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