From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter De Schrijver Subject: Re: [PATCH] clk: tegra: Use readl_relaxed_poll_timeout_atomic in tegra210_clock_init Date: Fri, 15 Sep 2017 12:31:45 +0300 Message-ID: <20170915093145.GD6290@tbergstrom-lnx.Nvidia.com> References: <1505439374-8666-1-git-send-email-nicoleotsuka@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <1505439374-8666-1-git-send-email-nicoleotsuka-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Nicolin Chen Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-clk-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org, thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, sboyd-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, mturquette-rdvid1DuHRBWk0Htik3J/w@public.gmane.org, pgaikwad-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org List-Id: linux-tegra@vger.kernel.org Apart from the typo in the commit message (preemption rather than preemtion): Acked-By: Peter De Schrijver 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 > --- > 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 >