| Message ID | 20210709122040.v5.3.Ifd87681955689a08cce4c65e72ee5e8c6d09af95@changeid (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Refactor MTK MDP driver into core/components | expand |
Hi Eizan, Thank you for your patch. On 9/7/21 4:23, Eizan Miyamoto wrote: > 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 <eizan@chromium.org> > --- > > (no changes since v1) > > drivers/media/platform/mtk-mdp/mtk_mdp_comp.c | 28 ++++++++++++++----- > drivers/media/platform/mtk-mdp/mtk_mdp_comp.h | 3 ++ > drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 23 ++++++++++----- > 3 files changed, 40 insertions(+), 14 deletions(-) > > diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c > index 8b6158379f41..ce54863c24ce 100644 > --- a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c > +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c > @@ -53,9 +53,9 @@ static const struct of_device_id mtk_mdp_comp_driver_dt_match[] = { > }; > MODULE_DEVICE_TABLE(of, mtk_mdp_comp_driver_dt_match); > > -void mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp) > +void mtk_mdp_comp_power_on(struct mtk_mdp_comp *comp) > { > - int i, err; > + int err; > > if (comp->larb_dev) { > err = mtk_smi_larb_get(comp->larb_dev); > @@ -66,9 +66,25 @@ void 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); You can do that change in the previous patch which is the one that introduces this dev_err call. > + > + mtk_mdp_comp_clock_on(comp); > +} > + > +void mtk_mdp_comp_power_off(struct mtk_mdp_comp *comp) > +{ > + int 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); > +} > + > +void mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp) > +{ > + int i, err; > > for (i = 0; i < ARRAY_SIZE(comp->clk); i++) { > if (IS_ERR(comp->clk[i])) > @@ -91,8 +107,6 @@ void mtk_mdp_comp_clock_off(struct mtk_mdp_comp *comp) > > if (comp->larb_dev) > mtk_smi_larb_put(comp->larb_dev); > - > - pm_runtime_put_sync(comp->dev); Ok, now that you are changing these functions I think it will be good to rework these clock_on and off properly. First returning an error when is needed and handling it properly on the error path instead of ignoring. > } > > static int mtk_mdp_comp_bind(struct device *dev, struct device *master, > diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h > index 5e2ee94a1b37..15ef9539a5a7 100644 > --- a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h > +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h > @@ -23,6 +23,9 @@ struct mtk_mdp_comp { > > int mtk_mdp_comp_init(struct mtk_mdp_comp *comp, struct device *dev); > > +void mtk_mdp_comp_power_on(struct mtk_mdp_comp *comp); > +void mtk_mdp_comp_power_off(struct mtk_mdp_comp *comp); > + > void mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp); > void mtk_mdp_comp_clock_off(struct mtk_mdp_comp *comp); > > diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c > index 78c40a61df1d..3558a6587f51 100644 > --- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c > +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c > @@ -54,8 +54,15 @@ static void mtk_mdp_clock_on(struct mtk_mdp_dev *mdp) > { > struct mtk_mdp_comp *comp_node; > > + /* > + * 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. > + */ > + mtk_mdp_comp_clock_on(&mdp->comp_self); > + > list_for_each_entry(comp_node, &mdp->comp_list, node) > - mtk_mdp_comp_clock_on(comp_node); > + mtk_mdp_comp_power_on(comp_node); > } > > static void mtk_mdp_clock_off(struct mtk_mdp_dev *mdp) > @@ -63,7 +70,14 @@ static void mtk_mdp_clock_off(struct mtk_mdp_dev *mdp) > struct mtk_mdp_comp *comp_node; > > list_for_each_entry(comp_node, &mdp->comp_list, node) > - mtk_mdp_comp_clock_off(comp_node); > + mtk_mdp_comp_power_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); > } > > static void mtk_mdp_wdt_worker(struct work_struct *work) > @@ -102,8 +116,6 @@ 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); > @@ -125,8 +137,6 @@ 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; > } > > @@ -137,7 +147,6 @@ 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 = { >
diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c index 8b6158379f41..ce54863c24ce 100644 --- a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.c @@ -53,9 +53,9 @@ static const struct of_device_id mtk_mdp_comp_driver_dt_match[] = { }; MODULE_DEVICE_TABLE(of, mtk_mdp_comp_driver_dt_match); -void mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp) +void mtk_mdp_comp_power_on(struct mtk_mdp_comp *comp) { - int i, err; + int err; if (comp->larb_dev) { err = mtk_smi_larb_get(comp->larb_dev); @@ -66,9 +66,25 @@ void 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); + + mtk_mdp_comp_clock_on(comp); +} + +void mtk_mdp_comp_power_off(struct mtk_mdp_comp *comp) +{ + int 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); +} + +void mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp) +{ + int i, err; for (i = 0; i < ARRAY_SIZE(comp->clk); i++) { if (IS_ERR(comp->clk[i])) @@ -91,8 +107,6 @@ void mtk_mdp_comp_clock_off(struct mtk_mdp_comp *comp) if (comp->larb_dev) mtk_smi_larb_put(comp->larb_dev); - - pm_runtime_put_sync(comp->dev); } static int mtk_mdp_comp_bind(struct device *dev, struct device *master, diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h index 5e2ee94a1b37..15ef9539a5a7 100644 --- a/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_comp.h @@ -23,6 +23,9 @@ struct mtk_mdp_comp { int mtk_mdp_comp_init(struct mtk_mdp_comp *comp, struct device *dev); +void mtk_mdp_comp_power_on(struct mtk_mdp_comp *comp); +void mtk_mdp_comp_power_off(struct mtk_mdp_comp *comp); + void mtk_mdp_comp_clock_on(struct mtk_mdp_comp *comp); void mtk_mdp_comp_clock_off(struct mtk_mdp_comp *comp); diff --git a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c index 78c40a61df1d..3558a6587f51 100644 --- a/drivers/media/platform/mtk-mdp/mtk_mdp_core.c +++ b/drivers/media/platform/mtk-mdp/mtk_mdp_core.c @@ -54,8 +54,15 @@ static void mtk_mdp_clock_on(struct mtk_mdp_dev *mdp) { struct mtk_mdp_comp *comp_node; + /* + * 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. + */ + mtk_mdp_comp_clock_on(&mdp->comp_self); + list_for_each_entry(comp_node, &mdp->comp_list, node) - mtk_mdp_comp_clock_on(comp_node); + mtk_mdp_comp_power_on(comp_node); } static void mtk_mdp_clock_off(struct mtk_mdp_dev *mdp) @@ -63,7 +70,14 @@ static void mtk_mdp_clock_off(struct mtk_mdp_dev *mdp) struct mtk_mdp_comp *comp_node; list_for_each_entry(comp_node, &mdp->comp_list, node) - mtk_mdp_comp_clock_off(comp_node); + mtk_mdp_comp_power_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); } static void mtk_mdp_wdt_worker(struct work_struct *work) @@ -102,8 +116,6 @@ 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); @@ -125,8 +137,6 @@ 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; } @@ -137,7 +147,6 @@ 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 = {
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 <eizan@chromium.org> --- (no changes since v1) drivers/media/platform/mtk-mdp/mtk_mdp_comp.c | 28 ++++++++++++++----- drivers/media/platform/mtk-mdp/mtk_mdp_comp.h | 3 ++ drivers/media/platform/mtk-mdp/mtk_mdp_core.c | 23 ++++++++++----- 3 files changed, 40 insertions(+), 14 deletions(-)