Hi,
On Thursday, June 30, 2011, jean.pihet@xxxxxxxxxxxxxx wrote:
> From: Jean Pihet <j-pihet@xxxxxx>
>
> The devices wake-up latency constraints class of PM QoS is
> storing the constraints list using the device pm_info struct.
>
> This patch adds the init and de-init of the per-device constraints
> list in order to support the dynamic insertion and removal
> of the devices in the system.
>
> Signed-off-by: Jean Pihet <j-pihet@xxxxxx>
The number of times this patch special cases PM_QOS_DEV_WAKEUP_LATENCY with
respect to the other PM QoS classes indicates a design issue, which kind of
corresponds with my comments on [3/11].
Thanks,
Rafael
> ---
> drivers/base/power/main.c | 8 +++--
> include/linux/pm.h | 1 +
> include/linux/pm_qos_params.h | 2 +
> kernel/pm_qos_params.c | 70 ++++++++++++++++++++++++++++++++--------
> 4 files changed, 64 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
> index b1fd96b..51f5526 100644
> --- a/drivers/base/power/main.c
> +++ b/drivers/base/power/main.c
> @@ -27,6 +27,7 @@
> #include <linux/sched.h>
> #include <linux/async.h>
> #include <linux/suspend.h>
> +#include <linux/pm_qos_params.h>
>
> #include "../base.h"
> #include "power.h"
> @@ -96,8 +97,8 @@ void device_pm_add(struct device *dev)
> dev_name(dev->parent));
> list_add_tail(&dev->power.entry, &dpm_list);
> mutex_unlock(&dpm_list_mtx);
> - /* ToDo: call PM QoS to init the per-device wakeup latency constraints */
> - plist_head_init(&dev->power.wakeup_lat_plist_head, &dev->power.lock);
> + /* Call PM QoS to init the per-device wakeup latency constraints */
> + pm_qos_dev_wakeup_lat_init(dev);
> }
>
> /**
> @@ -108,7 +109,8 @@ void device_pm_remove(struct device *dev)
> {
> pr_debug("PM: Removing info for %s:%s\n",
> dev->bus ? dev->bus->name : "No Bus", dev_name(dev));
> - /* ToDo: call PM QoS to de-init the per-device wakeup latency constraints */
> + /* Call PM QoS to de-init the per-device wakeup latency constraints */
> + pm_qos_dev_wakeup_lat_deinit(dev);
> complete_all(&dev->power.completion);
> mutex_lock(&dpm_list_mtx);
> list_del_init(&dev->power.entry);
> diff --git a/include/linux/pm.h b/include/linux/pm.h
> index 35fe682..d9b6092 100644
> --- a/include/linux/pm.h
> +++ b/include/linux/pm.h
> @@ -464,6 +464,7 @@ struct dev_pm_info {
> void *subsys_data; /* Owned by the subsystem. */
> #endif
> struct plist_head wakeup_lat_plist_head;
> + int wakeup_lat_init;
> };
>
> extern void update_pm_runtime_accounting(struct device *dev);
> diff --git a/include/linux/pm_qos_params.h b/include/linux/pm_qos_params.h
> index e6e16cb..5b6707a 100644
> --- a/include/linux/pm_qos_params.h
> +++ b/include/linux/pm_qos_params.h
> @@ -45,4 +45,6 @@ int pm_qos_add_notifier(int class, struct notifier_block *notifier);
> int pm_qos_remove_notifier(int class, struct notifier_block *notifier);
> int pm_qos_request_active(struct pm_qos_request_list *req);
>
> +void pm_qos_dev_wakeup_lat_init(struct device *dev);
> +void pm_qos_dev_wakeup_lat_deinit(struct device *dev);
> #endif
> diff --git a/kernel/pm_qos_params.c b/kernel/pm_qos_params.c
> index d61c8e5..6f25ccb 100644
> --- a/kernel/pm_qos_params.c
> +++ b/kernel/pm_qos_params.c
> @@ -275,11 +275,21 @@ void pm_qos_add_request(struct pm_qos_request_list *pm_qos_req,
> struct pm_qos_object *o = pm_qos_array[pm_qos_params->class];
> int new_value;
>
> - if ((pm_qos_params->class != PM_QOS_DEV_WAKEUP_LATENCY) &&
> - (pm_qos_request_active(pm_qos_req))) {
> - WARN(1, KERN_ERR "pm_qos_add_request() called for already "
> - "added request\n");
> - return;
> + if (pm_qos_params->class == PM_QOS_DEV_WAKEUP_LATENCY) {
> + if (!pm_qos_params->dev) {
> + WARN(1, KERN_ERR "pm_qos_add_request() called for "
> + "invalid device\n");
> + return;
> + }
> + /* Silently return if the device is being released */
> + if (!pm_qos_params->dev->power.wakeup_lat_init)
> + return;
> + } else {
> + if (pm_qos_request_active(pm_qos_req)) {
> + WARN(1, KERN_ERR "pm_qos_add_request() called for "
> + "already added request\n");
> + return;
> + }
> }
>
> if (pm_qos_params->value == PM_QOS_DEFAULT_VALUE)
> @@ -312,11 +322,16 @@ void pm_qos_update_request(struct pm_qos_request_list *pm_qos_req,
> if (!pm_qos_req) /*guard against callers passing in null */
> return;
>
> - if ((pm_qos_req->class != PM_QOS_DEV_WAKEUP_LATENCY) &&
> - (!pm_qos_request_active(pm_qos_req))) {
> - WARN(1, KERN_ERR "pm_qos_update_request() called for unknown "
> - "object\n");
> - return;
> + if (pm_qos_req->class == PM_QOS_DEV_WAKEUP_LATENCY) {
> + /* Silently return if the device is being released */
> + if (!pm_qos_req->dev->power.wakeup_lat_init)
> + return;
> + } else {
> + if (!pm_qos_request_active(pm_qos_req)) {
> + WARN(1, KERN_ERR "pm_qos_update_request() called "
> + "for unknown object\n");
> + return;
> + }
> }
>
> if (new_value == PM_QOS_DEFAULT_VALUE)
> @@ -343,11 +358,16 @@ void pm_qos_remove_request(struct pm_qos_request_list *pm_qos_req)
> return;
> /* silent return to keep pcm code cleaner */
>
> - if ((pm_qos_req->class != PM_QOS_DEV_WAKEUP_LATENCY) &&
> - (!pm_qos_request_active(pm_qos_req))) {
> - WARN(1, KERN_ERR "pm_qos_remove_request() called for unknown "
> - "object\n");
> + if (pm_qos_req->class == PM_QOS_DEV_WAKEUP_LATENCY) {
> + /* Silently return if the device is being released */
> + if (!pm_qos_req->dev->power.wakeup_lat_init)
> + return;
> + } else {
> + if (!pm_qos_request_active(pm_qos_req)) {
> + WARN(1, KERN_ERR "pm_qos_remove_request() called "
> + "for unknown object\n");
> return;
> + }
> }
>
> update_target(pm_qos_req, 1, PM_QOS_DEFAULT_VALUE);
> @@ -393,6 +413,28 @@ int pm_qos_remove_notifier(int class, struct notifier_block *notifier)
> }
> EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
>
> +/* Called from the device PM subsystem at device init */
> +void pm_qos_dev_wakeup_lat_init(struct device *dev)
> +{
> + plist_head_init(&dev->power.wakeup_lat_plist_head, &dev->power.lock);
> + dev->power.wakeup_lat_init = 1;
> +}
> +
> +/* Called from the device PM subsystem at device release */
> +void pm_qos_dev_wakeup_lat_deinit(struct device *dev)
> +{
> + struct pm_qos_request_list *req, *tmp;
> +
> + dev->power.wakeup_lat_init = 0;
> +
> + /* Flush the constraints list for the device */
> + plist_for_each_entry_safe(req, tmp,
> + &dev->power.wakeup_lat_plist_head,
> + list)
> + update_target(req, 1, PM_QOS_DEFAULT_VALUE);
> + plist_head_init(&dev->power.wakeup_lat_plist_head, &dev->power.lock);
> +}
> +
> static int pm_qos_power_open(struct inode *inode, struct file *filp)
> {
> struct pm_qos_parameters pm_qos_params;
>
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