clk: mediatek: Do a runtime PM get on controllers during probe
authorPin-yen Lin <treapking@chromium.org>
Tue, 12 Mar 2024 11:51:55 +0000 (19:51 +0800)
committerStephen Boyd <sboyd@kernel.org>
Thu, 11 Apr 2024 03:50:06 +0000 (20:50 -0700)
commit2f7b1d8b5505efb0057cd1ab85fca206063ea4c3
tree304f7f330a486848d6e94f561efb57f65fc3deae
parent754e5287c7d58cf13da02c57b25d5fcc718f12d5
clk: mediatek: Do a runtime PM get on controllers during probe

mt8183-mfgcfg has a mutual dependency with genpd during the probing
stage, which leads to a deadlock in the following call stack:

CPU0:  genpd_lock --> clk_prepare_lock
genpd_power_off_work_fn()
 genpd_lock()
 generic_pm_domain::power_off()
    clk_unprepare()
      clk_prepare_lock()

CPU1: clk_prepare_lock --> genpd_lock
clk_register()
  __clk_core_init()
    clk_prepare_lock()
    clk_pm_runtime_get()
      genpd_lock()

Do a runtime PM get at the probe function to make sure clk_register()
won't acquire the genpd lock. Instead of only modifying mt8183-mfgcfg,
do this on all mediatek clock controller probings because we don't
believe this would cause any regression.

Verified on MT8183 and MT8192 Chromebooks.

Fixes: acddfc2c261b ("clk: mediatek: Add MT8183 clock support")
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Link: https://lore.kernel.org/r/20240312115249.3341654-1-treapking@chromium.org
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
drivers/clk/mediatek/clk-mtk.c