| Message ID | 1519843555-982-1-git-send-email-fkan@apm.com |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | PM / core: move device and its children to end of dpm list | expand |
On Wed, Feb 28, 2018 at 10:45:55AM -0800, Feng Kan wrote: > When bridge and its endpoint is enumated the devices are added to the > dpm list. Afterward, the bridge defers probe when IOMMU is not ready. > This causes the bridge to be moved to the end of the dpm list when deferred > probe kicks in. The order of the dpm list for bridge and endpoint is > reversed. > > Add reordering code to re-position the bridge and its children so the order > for suspend and resume is not altered. > > Signed-off-by: Feng Kan <fkan@apm.com> > Signed-off-by: Toan Le <toanle@apm.com> > diff --git a/include/linux/device.h b/include/linux/device.h > index 9d32000..1ec12d5 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -1272,6 +1272,9 @@ extern void devm_device_remove_group(struct device *dev, > /* debugging and troubleshooting/diagnostic helpers. */ > extern const char *dev_driver_string(const struct device *dev); > > +/* reorder device and its children to end of dpm list */ > +void device_pm_reorder(struct device *dev); Do you expect drivers to use this, or only the driver core in drivers/base/? There is a drivers/base/base.h; maybe this would fit there rather than being exposed to the rest of the kernel via include/linux/device.h? > /* Device links interface. */ > struct device_link *device_link_add(struct device *consumer, > struct device *supplier, u32 flags); > -- > 1.8.3.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Wed, Feb 28, 2018 at 7:45 PM, Feng Kan <fkan@apm.com> wrote: > When bridge and its endpoint is enumated the devices are added to the > dpm list. Afterward, the bridge defers probe when IOMMU is not ready. > This causes the bridge to be moved to the end of the dpm list when deferred > probe kicks in. The order of the dpm list for bridge and endpoint is > reversed. > > Add reordering code to re-position the bridge and its children so the order > for suspend and resume is not altered. > > Signed-off-by: Feng Kan <fkan@apm.com> > Signed-off-by: Toan Le <toanle@apm.com> > --- > drivers/base/core.c | 20 ++++++++++++++++++++ > drivers/base/dd.c | 8 ++++---- > include/linux/device.h | 3 +++ > 3 files changed, 27 insertions(+), 4 deletions(-) > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index 110230d..0b4ad99 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -148,6 +148,26 @@ static int device_reorder_to_tail(struct device *dev, void *not_used) > } > > /** > + * device_pm_reorder - reorder device and its children to end of dpm list Not just the children and not just dpm_list. > + * @dev: current device pointer > + * > + * This is a lock held version of reordering the device to dpm list tail. > + * This will move the device to the end of the dpm list if it not registered. > + * Afterward, it will iterate through its children and do the same for them. This isn't entirely accurate as device_reorder_to_tail() does more than that. > + */ > +void device_pm_reorder(struct device *dev) I'd call it device_pm_move_to_tail() as that's what it does. "Reorder" is sort of overly generic IMO. > +{ > + int idx; > + > + idx = device_links_read_lock(); > + device_pm_lock(); > + device_reorder_to_tail(dev, NULL); > + device_pm_unlock(); > + device_links_read_unlock(idx); > +} > +EXPORT_SYMBOL_GPL(device_pm_reorder); It is not necessary to export this symbol. > + > +/** > * device_link_add - Create a link between two devices. > * @consumer: Consumer end of the link. > * @supplier: Supplier end of the link. > diff --git a/drivers/base/dd.c b/drivers/base/dd.c > index 2c964f5..3223a30 100644 > --- a/drivers/base/dd.c > +++ b/drivers/base/dd.c > @@ -121,11 +121,11 @@ static void deferred_probe_work_func(struct work_struct *work) > * Force the device to the end of the dpm_list since > * the PM code assumes that the order we add things to > * the list is a good order for suspend but deferred > - * probe makes that very unsafe. > + * probe makes that very unsafe. Also move any children > + * belong to the device to the end of the list as well. > + * This way the suspend resume order won't be corrupted. > */ > - device_pm_lock(); > - device_pm_move_last(dev); > - device_pm_unlock(); > + device_pm_reorder(dev); > > dev_dbg(dev, "Retrying from deferred list\n"); > if (initcall_debug && !initcalls_done) > diff --git a/include/linux/device.h b/include/linux/device.h > index 9d32000..1ec12d5 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -1272,6 +1272,9 @@ extern void devm_device_remove_group(struct device *dev, > /* debugging and troubleshooting/diagnostic helpers. */ > extern const char *dev_driver_string(const struct device *dev); > > +/* reorder device and its children to end of dpm list */ > +void device_pm_reorder(struct device *dev); And this header can go into drivers/base/base.h as Bjorn said. > + > /* Device links interface. */ > struct device_link *device_link_add(struct device *consumer, > struct device *supplier, u32 flags); > -- > 1.8.3.1 >
diff --git a/drivers/base/core.c b/drivers/base/core.c index 110230d..0b4ad99 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -148,6 +148,26 @@ static int device_reorder_to_tail(struct device *dev, void *not_used) } /** + * device_pm_reorder - reorder device and its children to end of dpm list + * @dev: current device pointer + * + * This is a lock held version of reordering the device to dpm list tail. + * This will move the device to the end of the dpm list if it not registered. + * Afterward, it will iterate through its children and do the same for them. + */ +void device_pm_reorder(struct device *dev) +{ + int idx; + + idx = device_links_read_lock(); + device_pm_lock(); + device_reorder_to_tail(dev, NULL); + device_pm_unlock(); + device_links_read_unlock(idx); +} +EXPORT_SYMBOL_GPL(device_pm_reorder); + +/** * device_link_add - Create a link between two devices. * @consumer: Consumer end of the link. * @supplier: Supplier end of the link. diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 2c964f5..3223a30 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -121,11 +121,11 @@ static void deferred_probe_work_func(struct work_struct *work) * Force the device to the end of the dpm_list since * the PM code assumes that the order we add things to * the list is a good order for suspend but deferred - * probe makes that very unsafe. + * probe makes that very unsafe. Also move any children + * belong to the device to the end of the list as well. + * This way the suspend resume order won't be corrupted. */ - device_pm_lock(); - device_pm_move_last(dev); - device_pm_unlock(); + device_pm_reorder(dev); dev_dbg(dev, "Retrying from deferred list\n"); if (initcall_debug && !initcalls_done) diff --git a/include/linux/device.h b/include/linux/device.h index 9d32000..1ec12d5 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -1272,6 +1272,9 @@ extern void devm_device_remove_group(struct device *dev, /* debugging and troubleshooting/diagnostic helpers. */ extern const char *dev_driver_string(const struct device *dev); +/* reorder device and its children to end of dpm list */ +void device_pm_reorder(struct device *dev); + /* Device links interface. */ struct device_link *device_link_add(struct device *consumer, struct device *supplier, u32 flags);