[PATCH v7 4/7] media: mtk-mdp: don't pm_run_time_get/put for master comp in clock_on
From: Eizan Miyamoto <hidden>
Date: 2021-08-25 06:34:26
Also in:
linux-arm-kernel, linux-mediatek, lkml
Subsystem:
media input infrastructure (v4l/dvb), the rest · Maintainers:
Mauro Carvalho Chehab, Linus Torvalds
The original intent of commit 86698b9505bbc ("media: mtk-mdp: convert
mtk_mdp_dev.comp array to list") was to create a list to track all the
MDP components that needed to have their clocks enabled/disabled when
calling mtk_mdp_comp_clock_on/off. However, there was a bug inside
mtk_mdp_register_component where the args to a call to list_add were
swapped. The result is that only one component was added to
mtk_mdp_dev.comp_list because comp_list was instead being
repeatedly added to the single element lists headed by each
mtk_mdp_comp.
The order of the args to list_add in mtk_mdp_register_component was
fixed in https://patchwork.kernel.org/patch/11742895/ (Fix Null pointer
dereference when calling list_add).
Then, as a result of https://patchwork.kernel.org/patch/11530769/
(mtk-mdp: use pm_runtime in MDP component driver) if all the components
are added to the component list, the mdp "master" / rdma0 component
ends up having pm_runtime_get_sync() called on it twice recursively:
rpm_resume+0x694/0x8f8
__pm_runtime_resume+0x7c/0xa0 ***NOTE***
mtk_mdp_comp_clock_on+0x48/0x104 [mtk_mdp]
mtk_mdp_pm_resume+0x2c/0x44 [mtk_mdp]
pm_generic_runtime_resume+0x34/0x48
__genpd_runtime_resume+0x6c/0x80
genpd_runtime_resume+0x104/0x1ac
__rpm_callback+0x120/0x238
rpm_callback+0x34/0x8c
rpm_resume+0x7a0/0x8f8
__pm_runtime_resume+0x7c/0xa0 ***NOTE***
mtk_mdp_m2m_start_streaming+0x2c/0x3c [mtk_mdp]
(The calls to pm_runtime_get_sync are inlined and correspond to the
calls to __pm_runtime_resume). It is not correct to have
pm_runtime_get_sync called recursively and the second call will block
indefinitely.
As a result of all that, this change factors mtk_mdp_comp_clock_on/off
into mtk_mdp_comp_power_on/off and moves the calls to
pm_runtime_get/put into the power_on/off functions.
This change then special-cases the master/rdma0 MDP component and does
these things:
- the master/rdma0 component is not added to mtk_mdp_dev.comp_list
- the master/rdma0 component has its clocks (*but not power*) toggled
by mtk_mpd_comp_clock_on/off inside mtk_mdp_clock_on/off.
- the other components have their clocks *and* power toggled with
mtk_mdp_comp_power_on/off.
This change introduces the assumption that mtk_mdp_pm_resume will
always be called though a callback from pm_runtime_get_sync made on the
master / rdma0 component.
Signed-off-by: Eizan Miyamoto <redacted>
Reviewed-by: Houlong Wei <houlong.wei@mediatek.com>
---
(no changes since v1)
drivers/media/platform/mtk-mdp/mtk_mdp_comp.c | 57 ++++++++++++++---
drivers/media/platform/mtk-mdp/mtk_mdp_comp.h | 5 +-
drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 62 ++++++++++++++-----
3 files changed, 98 insertions(+), 26 deletions(-)
diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
index 472c261b01e8..7b6c8a3f3455 100644
--- a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c
+++ b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c@@ -51,9 +51,9 @@ static const struct of_device_id mtk_mdp_comp_driver_dt_match[] = { }; MODULE_DEVICE_TABLE(of, mtk_mdp_comp_driver_dt_match); -int mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp) +int mtk_mdp_comp_power_on(struct mtk_mdp_comp *comp) { - int i, err, status; + int status, err; if (comp->larb_dev) { err = mtk_smi_larb_get(comp->larb_dev);
@@ -63,12 +63,54 @@ int mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp) err = pm_runtime_get_sync(comp->dev); if (err < 0) { - dev_err(comp->dev, - "failed to runtime get, err %d.\n", - err); + dev_err(comp->dev, "failed to runtime get, err %d.\n", err); return err; } + err = mtk_mdp_comp_clock_on(comp); + if (err) { + dev_err(comp->dev, "failed to turn on clock. err=%d", err); + status = err; + goto err_mtk_mdp_comp_clock_on; + } + + return 0; + +err_mtk_mdp_comp_clock_on: + err = pm_runtime_put_sync(comp->dev); + if (err) + dev_err(comp->dev, "failed to runtime put in cleanup. err=%d", err); + + return status; +} + +int mtk_mdp_comp_power_off(struct mtk_mdp_comp *comp) +{ + int status, err; + + mtk_mdp_comp_clock_off(comp); + + err = pm_runtime_put_sync(comp->dev); + if (err < 0) { + dev_err(comp->dev, "failed to runtime put, err %d.\n", err); + status = err; + goto err_pm_runtime_put_sync; + } + + return 0; + +err_pm_runtime_put_sync: + err = mtk_mdp_comp_clock_on(comp); + if (err) + dev_err(comp->dev, "failed to turn on clock in cleanup. err=%d", err); + + return status; +} + +int mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp) +{ + int i, err, status; + for (i = 0; i < ARRAY_SIZE(comp->clk); i++) { if (IS_ERR(comp->clk[i])) continue;
@@ -94,7 +136,8 @@ int mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp) return status; } -int mtk_mdp_comp_clock_off(struct mtk_mdp_comp *comp) + +void mtk_mdp_comp_clock_off(struct mtk_mdp_comp *comp) { int i;
@@ -106,8 +149,6 @@ int mtk_mdp_comp_clock_off(struct mtk_mdp_comp *comp) if (comp->larb_dev) mtk_smi_larb_put(comp->larb_dev); - - return pm_runtime_put_sync(comp->dev); } static int mtk_mdp_comp_bind(struct device *dev, struct device *master, void *data)
diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h
index f2e22e7e7c45..e3d6aef52869 100644
--- a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h
+++ b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h@@ -23,8 +23,11 @@ struct mtk_mdp_comp { int mtk_mdp_comp_init(struct mtk_mdp_comp *comp, struct device *dev); +int mtk_mdp_comp_power_on(struct mtk_mdp_comp *comp); +int mtk_mdp_comp_power_off(struct mtk_mdp_comp *comp); + int mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp); -int mtk_mdp_comp_clock_off(struct mtk_mdp_comp *comp); +void mtk_mdp_comp_clock_off(struct mtk_mdp_comp *comp); extern struct platform_driver mtk_mdp_component_driver;
diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
index 714154450981..a72a9ba41ea6 100644
--- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c
+++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c@@ -57,29 +57,64 @@ static int mtk_mdp_clock_on(struct mtk_mdp_dev *mdp) struct device *dev = &mdp->pdev->dev; int err; + /* + * The master / rdma0 component will have pm_runtime_get_sync called + * on it through mtk_mdp_m2m_start_streaming, making it unnecessary to + * have mtk_mdp_comp_power_on called on it. + */ + err = mtk_mdp_comp_clock_on(&mdp->comp_self); + if (err) + return err; + list_for_each_entry(comp_node, &mdp->comp_list, node) { - err = mtk_mdp_comp_clock_on(comp_node); + err = mtk_mdp_comp_power_on(comp_node); if (err) { status = err; - goto err_mtk_mdp_comp_clock_on; + goto err_mtk_mdp_comp_power_on; } } return 0; -err_mtk_mdp_comp_clock_on: - list_for_each_entry_continue_reverse(comp_node, &mdp->comp_list, node) - mtk_mdp_comp_clock_off(comp_node); - +err_mtk_mdp_comp_power_on: + list_for_each_entry_continue_reverse(comp_node, &mdp->comp_list, node) { + err = mtk_mdp_comp_power_off(comp_node); + if (err) + dev_err(&mdp->pdev->dev, "failed to power off after error. err=%d", err); + } return status; } -static void mtk_mdp_clock_off(struct mtk_mdp_dev *mdp) +static int mtk_mdp_clock_off(struct mtk_mdp_dev *mdp) { struct mtk_mdp_comp *comp_node; + int status, err; + + list_for_each_entry(comp_node, &mdp->comp_list, node) { + err = mtk_mdp_comp_power_off(comp_node); + if (err) { + status = err; + goto err_mtk_mdp_comp_power_off; + } + } - list_for_each_entry(comp_node, &mdp->comp_list, node) - mtk_mdp_comp_clock_off(comp_node); + /* + * The master / rdma0 component will have pm_runtime_put called + * on it through mtk_mdp_m2m_stop_streaming, making it unnecessary to + * have mtk_mdp_comp_power_off called on it. + */ + mtk_mdp_comp_clock_off(&mdp->comp_self); + + return 0; + +err_mtk_mdp_comp_power_off: + list_for_each_entry_continue_reverse(comp_node, &mdp->comp_list, node) { + err = mtk_mdp_comp_power_on(comp_node); + if (err) + dev_err(&mdp->pdev->dev, "failed to power on after error. err=%d", err); + } + + return status; } static void mtk_mdp_wdt_worker(struct work_struct *work)
@@ -118,8 +153,6 @@ static int mtk_mdp_master_bind(struct device *dev) int status; struct mtk_mdp_dev *mdp = dev_get_drvdata(dev); - mtk_mdp_register_component(mdp, &mdp->comp_self); - status = component_bind_all(dev, mdp); if (status) { dev_err(dev, "Failed to bind all components: %d\n", status);
@@ -140,8 +173,6 @@ static int mtk_mdp_master_bind(struct device *dev) component_unbind_all(dev, mdp); err_component_bind_all: - mtk_mdp_unregister_component(mdp, &mdp->comp_self); - return status; }
@@ -152,7 +183,6 @@ static void mtk_mdp_master_unbind(struct device *dev) pm_runtime_disable(dev); mtk_mdp_unregister_m2m_device(mdp); component_unbind_all(dev, mdp); - mtk_mdp_unregister_component(mdp, &mdp->comp_self); } static const struct component_master_ops mtk_mdp_com_ops = {
@@ -337,9 +367,7 @@ static int __maybe_unused mtk_mdp_pm_suspend(struct device *dev) { struct mtk_mdp_dev *mdp = dev_get_drvdata(dev); - mtk_mdp_clock_off(mdp); - - return 0; + return mtk_mdp_clock_off(mdp); } static int __maybe_unused mtk_mdp_pm_resume(struct device *dev)
--
2.33.0.rc2.250.ged5fa647cd-goog