Messages in this thread | | | Date | Tue, 4 Jul 2023 22:54:51 +0300 | From | Dmitry Rokosov <> | Subject | Re: [PATCH v1] clk: meson: change usleep_range() to udelay() for atomic context |
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Hello Jerome,
Thank you for the review!
On Tue, Jul 04, 2023 at 09:43:41PM +0200, Jerome Brunet wrote: > > On Mon 03 Jul 2023 at 23:04, Dmitry Rokosov <ddrokosov@sberdevices.ru> wrote: > > > The function meson_clk_pll_enable() can be invoked under the enable_lock > > spinlock from the clk core logic > > --- > > (please refer to > > drivers/clk/clk.c:clk_core_enable_lock()), which risks a kernel panic > > during the usleep_range() call: > > > > This part of the comment is not very useful - please drop it >
Do you mean a stack trace or reference to clk_core_enable_lock()?
> > BUG: scheduling while atomic: kworker/u4:2/36/0x00000002 > > Modules linked in: g_ffs usb_f_fs libcomposite > > CPU: 1 PID: 36 Comm: kworker/u4:2 Not tainted 6.4.0-rc5 #273 > > Workqueue: events_unbound async_run_entry_fn > > Call trace: > > dump_backtrace+0x9c/0x128 > > show_stack+0x20/0x38 > > dump_stack_lvl+0x48/0x60 > > dump_stack+0x18/0x28 > > __schedule_bug+0x58/0x78 > > __schedule+0x828/0xa88 > > schedule+0x64/0xd8 > > schedule_hrtimeout_range_clock+0xd0/0x208 > > schedule_hrtimeout_range+0x1c/0x30 > > usleep_range_state+0x6c/0xa8 > > meson_clk_pll_enable+0x1f4/0x310 > > clk_core_enable+0x78/0x200 > > clk_core_enable+0x58/0x200 > > clk_core_enable+0x58/0x200 > > clk_core_enable+0x58/0x200 > > clk_enable+0x34/0x60 > > > > Considering that this code is expected to be used in an atomic context, > > it is required to use the udelay() function instead of usleep_range() > > for the atomic context safety. > > Please use an imperative form, instructing the code to change >
Ack
> > > > Fixes: b6ec400aa153 ("clk: meson: introduce new pll power-on sequence for A1 SoC family") > > Reported-by: Jan Dakinevich <yvdakinevich@sberdevices.ru> > > Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> > > Signed-off-by: Jan Dakinevich <yvdakinevich@sberdevices.ru> > > The tags are confusing here > I suppose a 2 lines change has not be been written with 4 hands ;) > > If Jan just reported and you made the change then drop his signed-off > If he did the job, then drop the reported-by and change the author >
No problem :) Sometimes 2 lines change is produced during 4 hands debugging :)
> > --- > > drivers/clk/meson/clk-pll.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c > > index 56ec2210f1ad..eef6f37c8d8d 100644 > > --- a/drivers/clk/meson/clk-pll.c > > +++ b/drivers/clk/meson/clk-pll.c > > @@ -367,9 +367,9 @@ static int meson_clk_pll_enable(struct clk_hw *hw) > > * 3. enable the lock detect module > > */ > > if (MESON_PARM_APPLICABLE(&pll->current_en)) { > > - usleep_range(10, 20); > > + udelay(10); > > meson_parm_write(clk->map, &pll->current_en, 1); > > - usleep_range(40, 50); > > + udelay(40); > > }; > > > > if (MESON_PARM_APPLICABLE(&pll->l_detect)) { >
-- Thank you, Dmitry
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