From: Chen-Yu Tsai wenst@chromium.org
stable inclusion from stable-v5.10.142 commit c0f0ed9ef9b625ca0584d54c55b3f8117cfabf47 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6CSFH
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
[ Upstream commit 35b0fac808b95eea1212f8860baf6ad25b88b087 ]
In the previous commits that added CLK_OPS_PARENT_ENABLE, support for this flag was only added to rate change operations (rate setting and reparent) and disabling unused subtree. It was not added to the clock gate related operations. Any hardware driver that needs it for these operations will either see bogus results, or worse, hang.
This has been seen on MT8192 and MT8195, where the imp_ii2_* clk drivers set this, but dumping debugfs clk_summary would cause it to hang.
Fixes: fc8726a2c021 ("clk: core: support clocks which requires parents enable (part 2)") Fixes: a4b3518d146f ("clk: core: support clocks which requires parents enable (part 1)") Signed-off-by: Chen-Yu Tsai wenst@chromium.org Reviewed-by: Nícolas F. R. A. Prado nfraprado@collabora.com Tested-by: Nícolas F. R. A. Prado nfraprado@collabora.com Link: https://lore.kernel.org/r/20220822081424.1310926-2-wenst@chromium.org Signed-off-by: Stephen Boyd sboyd@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Jialin Zhang zhangjialin11@huawei.com Reviewed-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/clk/clk.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 2e56cc0a3bce..4f20d5318183 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -203,6 +203,9 @@ static bool clk_core_rate_is_protected(struct clk_core *core) return core->protect_count; }
+static int clk_core_prepare_enable(struct clk_core *core); +static void clk_core_disable_unprepare(struct clk_core *core); + static bool clk_core_is_prepared(struct clk_core *core) { bool ret = false; @@ -215,7 +218,11 @@ static bool clk_core_is_prepared(struct clk_core *core) return core->prepare_count;
if (!clk_pm_runtime_get(core)) { + if (core->flags & CLK_OPS_PARENT_ENABLE) + clk_core_prepare_enable(core->parent); ret = core->ops->is_prepared(core->hw); + if (core->flags & CLK_OPS_PARENT_ENABLE) + clk_core_disable_unprepare(core->parent); clk_pm_runtime_put(core); }
@@ -251,7 +258,13 @@ static bool clk_core_is_enabled(struct clk_core *core) } }
+ if (core->flags & CLK_OPS_PARENT_ENABLE) + clk_core_prepare_enable(core->parent); + ret = core->ops->is_enabled(core->hw); + + if (core->flags & CLK_OPS_PARENT_ENABLE) + clk_core_disable_unprepare(core->parent); done: if (core->rpm_enabled) pm_runtime_put(core->dev); @@ -818,6 +831,9 @@ int clk_rate_exclusive_get(struct clk *clk) } EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
+static int clk_core_enable_lock(struct clk_core *core); +static void clk_core_disable_lock(struct clk_core *core); + static void clk_core_unprepare(struct clk_core *core) { lockdep_assert_held(&prepare_lock); @@ -841,6 +857,9 @@ static void clk_core_unprepare(struct clk_core *core)
WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
+ if (core->flags & CLK_OPS_PARENT_ENABLE) + clk_core_enable_lock(core->parent); + trace_clk_unprepare(core);
if (core->ops->unprepare) @@ -849,6 +868,9 @@ static void clk_core_unprepare(struct clk_core *core) clk_pm_runtime_put(core);
trace_clk_unprepare_complete(core); + + if (core->flags & CLK_OPS_PARENT_ENABLE) + clk_core_disable_lock(core->parent); clk_core_unprepare(core->parent); }
@@ -897,6 +919,9 @@ static int clk_core_prepare(struct clk_core *core) if (ret) goto runtime_put;
+ if (core->flags & CLK_OPS_PARENT_ENABLE) + clk_core_enable_lock(core->parent); + trace_clk_prepare(core);
if (core->ops->prepare) @@ -904,6 +929,9 @@ static int clk_core_prepare(struct clk_core *core)
trace_clk_prepare_complete(core);
+ if (core->flags & CLK_OPS_PARENT_ENABLE) + clk_core_disable_lock(core->parent); + if (ret) goto unprepare; }