From: Tony Lindgren <tony@atomide.com>
To: Keerthy <j-keerthy@ti.com>
Cc: Michael Turquette <mturquette@baylibre.com>,
Stephen Boyd <sboyd@codeaurora.org>,
Tero Kristo <t-kristo@ti.com>,
devicetree@vger.kernel.org, linux-clk@vger.kernel.org,
linux-omap@vger.kernel.org
Subject: Re: [PATCH] clk: ti: clkctrl: Fix failed to enable error with double udelay timeout
Date: Thu, 10 Oct 2019 07:05:19 -0700 [thread overview]
Message-ID: <20191010140519.GV5610@atomide.com> (raw)
In-Reply-To: <93a6448d-cece-a903-5c7e-ade793d62063@ti.com>
* Keerthy <j-keerthy@ti.com> [191007 00:57]:
>
>
> On 30/09/19 9:10 PM, Tony Lindgren wrote:
> > Commit 3d8598fb9c5a ("clk: ti: clkctrl: use fallback udelay approach if
> > timekeeping is suspended") added handling for cases when timekeeping is
> > suspended. But looks like we can still get occasional "failed to enable"
> > errors on the PM runtime resume path with udelay() returning faster than
> > expected.
> >
> > With ti-sysc interconnect target module driver this leads into device
> > failure with PM runtime failing with "failed to enable" clkctrl error.
> >
> > Let's fix the issue with a delay of two times the desired delay as in
> > often done for udelay() to account for the inaccuracy.
>
> Tested for DS0 and rtc+ddr modes on am43 and ds0 on am33.
>
> Tested-by: Keerthy <j-keerthy@ti.com>
Thanks for testing. This one should be applied into v5.4-rc series
please if no more comments.
Regards,
Tony
> > Fixes: 3d8598fb9c5a ("clk: ti: clkctrl: use fallback udelay approach if timekeeping is suspended")
> > Cc: Keerthy <j-keerthy@ti.com>
> > Cc: Tero Kristo <t-kristo@ti.com>
> > Signed-off-by: Tony Lindgren <tony@atomide.com>
> > ---
> > drivers/clk/ti/clkctrl.c | 5 +++--
> > 1 file changed, 3 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/clk/ti/clkctrl.c b/drivers/clk/ti/clkctrl.c
> > --- a/drivers/clk/ti/clkctrl.c
> > +++ b/drivers/clk/ti/clkctrl.c
> > @@ -100,11 +100,12 @@ static bool _omap4_is_timeout(union omap4_timeout *time, u32 timeout)
> > * can be from a timer that requires pm_runtime access, which
> > * will eventually bring us here with timekeeping_suspended,
> > * during both suspend entry and resume paths. This happens
> > - * at least on am43xx platform.
> > + * at least on am43xx platform. Account for flakeyness
> > + * with udelay() by multiplying the timeout value by 2.
> > */
> > if (unlikely(_early_timeout || timekeeping_suspended)) {
> > if (time->cycles++ < timeout) {
> > - udelay(1);
> > + udelay(1 * 2);
> > return false;
> > }
> > } else {
> >
next prev parent reply other threads:[~2019-10-10 14:05 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-30 15:40 [PATCH] clk: ti: clkctrl: Fix failed to enable error with double udelay timeout Tony Lindgren
2019-10-07 0:57 ` Keerthy
2019-10-10 14:05 ` Tony Lindgren [this message]
2019-10-24 8:00 ` Tero Kristo
2019-11-04 17:57 ` Stephen Boyd
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