| Message ID | 1606303396-5588-1-git-send-email-loic.poulain@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v4] bus: mhi: core: Fix device hierarchy | expand |
On Wed, Nov 25, 2020 at 12:23:16PM +0100, Loic Poulain wrote: > This patch fixes the hierarchical structure of MHI devices. Indeed, > MHI client devices are directly 'enumerated' from the mhi controller > and therefore must be direct descendants/children of their mhi > controller device, in accordance with the Linux Device Model. > > Today both MHI clients and controller devices are at the same level, > this patch ensures that MHI controller is parent of its client devices. > > The hierarc /* Only destroy virtual devices thats attached to bus */ if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER) return 0;hy is especially important for power management (safe > suspend/resume order). It is also useful for userspace to determine > relationship between MHI client devices and controllers. > > Signed-off-by: Loic Poulain <loic.poulain@linaro.org> > Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> > --- > v2: fix commit message > v3: reword commit message > v4: fix device destroy > > drivers/bus/mhi/core/init.c | 10 +++++++++- > drivers/bus/mhi/core/pm.c | 4 ++-- > 2 files changed, 11 insertions(+), 3 deletions(-) > > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c > index 436221c..c7a7354 100644 > --- a/drivers/bus/mhi/core/init.c > +++ b/drivers/bus/mhi/core/init.c > @@ -1137,7 +1137,15 @@ struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl) > device_initialize(dev); > dev->bus = &mhi_bus_type; > dev->release = mhi_release_device; > - dev->parent = mhi_cntrl->cntrl_dev; > + > + if (mhi_cntrl->mhi_dev) { > + /* for MHI client devices, parent is the MHI controller device */ > + dev->parent = &mhi_cntrl->mhi_dev->dev; > + } else { > + /* for MHI controller device, parent is the bus device (e.g. pci device) */ > + dev->parent = mhi_cntrl->cntrl_dev; > + } > + > mhi_dev->mhi_cntrl = mhi_cntrl; > mhi_dev->dev_wake = 0; > > diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c > index a671f58..681960c 100644 > --- a/drivers/bus/mhi/core/pm.c > +++ b/drivers/bus/mhi/core/pm.c > @@ -504,7 +504,7 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl) > wake_up_all(&mhi_cntrl->state_event); > > dev_dbg(dev, "Reset all active channels and remove MHI devices\n"); > - device_for_each_child(mhi_cntrl->cntrl_dev, NULL, mhi_destroy_device); > + device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device); > > mutex_lock(&mhi_cntrl->pm_mutex); > > @@ -637,7 +637,7 @@ static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl) > wake_up_all(&mhi_cntrl->state_event); > > dev_dbg(dev, "Reset all active channels and remove MHI devices\n"); > - device_for_each_child(mhi_cntrl->cntrl_dev, NULL, mhi_destroy_device); > + device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device); Hmm. Now I don't think we need below check in mhi_destroy_device(): /* Only destroy virtual devices thats attached to bus */ if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER) return 0; But let's keep it there for sanity. Have you looked into mhi_debugfs_devices_show()? I guess you need to call device_for_each_child() for both "mhi_cntrl->cntrl_dev" and "mhi_cntrl->mhi_dev->dev". Thanks, Mani > > mutex_lock(&mhi_cntrl->pm_mutex); > > -- > 2.7.4 >
On Wed, 25 Nov 2020 at 12:58, Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> wrote: > > On Wed, Nov 25, 2020 at 12:23:16PM +0100, Loic Poulain wrote: > > This patch fixes the hierarchical structure of MHI devices. Indeed, > > MHI client devices are directly 'enumerated' from the mhi controller > > and therefore must be direct descendants/children of their mhi > > controller device, in accordance with the Linux Device Model. > > > > Today both MHI clients and controller devices are at the same level, > > this patch ensures that MHI controller is parent of its client devices. > > > > The hierarc /* Only destroy virtual devices thats attached to bus */ > if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER) > return 0;hy is especially important for power management (safe > > suspend/resume order). It is also useful for userspace to determine > > relationship between MHI client devices and controllers. > > > > Signed-off-by: Loic Poulain <loic.poulain@linaro.org> > > Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> > > --- > > v2: fix commit message > > v3: reword commit message > > v4: fix device destroy > > > > drivers/bus/mhi/core/init.c | 10 +++++++++- > > drivers/bus/mhi/core/pm.c | 4 ++-- > > 2 files changed, 11 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c > > index 436221c..c7a7354 100644 > > --- a/drivers/bus/mhi/core/init.c > > +++ b/drivers/bus/mhi/core/init.c > > @@ -1137,7 +1137,15 @@ struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl) > > device_initialize(dev); > > dev->bus = &mhi_bus_type; > > dev->release = mhi_release_device; > > - dev->parent = mhi_cntrl->cntrl_dev; > > + > > + if (mhi_cntrl->mhi_dev) { > > + /* for MHI client devices, parent is the MHI controller device */ > > + dev->parent = &mhi_cntrl->mhi_dev->dev; > > + } else { > > + /* for MHI controller device, parent is the bus device (e.g. pci device) */ > > + dev->parent = mhi_cntrl->cntrl_dev; > > + } > > + > > mhi_dev->mhi_cntrl = mhi_cntrl; > > mhi_dev->dev_wake = 0; > > > > diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c > > index a671f58..681960c 100644 > > --- a/drivers/bus/mhi/core/pm.c > > +++ b/drivers/bus/mhi/core/pm.c > > @@ -504,7 +504,7 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl) > > wake_up_all(&mhi_cntrl->state_event); > > > > dev_dbg(dev, "Reset all active channels and remove MHI devices\n"); > > - device_for_each_child(mhi_cntrl->cntrl_dev, NULL, mhi_destroy_device); > > + device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device); > > > > mutex_lock(&mhi_cntrl->pm_mutex); > > > > @@ -637,7 +637,7 @@ static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl) > > wake_up_all(&mhi_cntrl->state_event); > > > > dev_dbg(dev, "Reset all active channels and remove MHI devices\n"); > > - device_for_each_child(mhi_cntrl->cntrl_dev, NULL, mhi_destroy_device); > > + device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device); > > Hmm. Now I don't think we need below check in mhi_destroy_device(): > > /* Only destroy virtual devices thats attached to bus */ > if (mhi_dev->dev_type == MHI_DEVICE_CONTROLLER) > return 0; > > But let's keep it there for sanity. right. > > Have you looked into mhi_debugfs_devices_show()? I guess you need to call > device_for_each_child() for both "mhi_cntrl->cntrl_dev" and > "mhi_cntrl->mhi_dev->dev". Yes, good point, going to address that. Loic
diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c index 436221c..c7a7354 100644 --- a/drivers/bus/mhi/core/init.c +++ b/drivers/bus/mhi/core/init.c @@ -1137,7 +1137,15 @@ struct mhi_device *mhi_alloc_device(struct mhi_controller *mhi_cntrl) device_initialize(dev); dev->bus = &mhi_bus_type; dev->release = mhi_release_device; - dev->parent = mhi_cntrl->cntrl_dev; + + if (mhi_cntrl->mhi_dev) { + /* for MHI client devices, parent is the MHI controller device */ + dev->parent = &mhi_cntrl->mhi_dev->dev; + } else { + /* for MHI controller device, parent is the bus device (e.g. pci device) */ + dev->parent = mhi_cntrl->cntrl_dev; + } + mhi_dev->mhi_cntrl = mhi_cntrl; mhi_dev->dev_wake = 0; diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c index a671f58..681960c 100644 --- a/drivers/bus/mhi/core/pm.c +++ b/drivers/bus/mhi/core/pm.c @@ -504,7 +504,7 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl) wake_up_all(&mhi_cntrl->state_event); dev_dbg(dev, "Reset all active channels and remove MHI devices\n"); - device_for_each_child(mhi_cntrl->cntrl_dev, NULL, mhi_destroy_device); + device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device); mutex_lock(&mhi_cntrl->pm_mutex); @@ -637,7 +637,7 @@ static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl) wake_up_all(&mhi_cntrl->state_event); dev_dbg(dev, "Reset all active channels and remove MHI devices\n"); - device_for_each_child(mhi_cntrl->cntrl_dev, NULL, mhi_destroy_device); + device_for_each_child(&mhi_cntrl->mhi_dev->dev, NULL, mhi_destroy_device); mutex_lock(&mhi_cntrl->pm_mutex);