diff options
| author |   Dmitry Rokosov <ddrokosov@sberdevices.ru> | 2023-07-05 00:54:04 +0300 |
|---|---|---|
| committer |   Jerome Brunet <jbrunet@baylibre.com> | 2023-07-11 11:35:42 +0200 |
| commit | 6e2acbfe59b83043bc7ae1bb39fac4fc9dcd5a18 (patch) | |
| tree | 55f03f004f50c1a36c1672ed34c72fc0137d37f8 /drivers/clk/meson | |
| parent | Linux 6.5-rc1 (diff) | |
| download | wireguard-linux-6e2acbfe59b83043bc7ae1bb39fac4fc9dcd5a18.tar.xz wireguard-linux-6e2acbfe59b83043bc7ae1bb39fac4fc9dcd5a18.zip | |
clk: meson: change usleep_range() to udelay() for atomic context
The function meson_clk_pll_enable() can be invoked under the enable_lock
spinlock from the clk core logic, which risks a kernel panic during the
usleep_range() call:
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
So it is required to use the udelay() function instead of usleep_range()
for the atomic context safety.
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>
Link: https://lore.kernel.org/r/20230704215404.11533-1-ddrokosov@sberdevices.ru
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Diffstat (limited to 'drivers/clk/meson')
| -rw-r--r-- | drivers/clk/meson/clk-pll.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c index 8fef90bf962f..6fa7639a3050 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)) { |