mmc: enable mmc host device to suspend/resume asynchronously

Now, PM core supports asynchronous suspend/resume mode for devices during system suspend/resume, and the power state transition of one device may be completed in separate kernel thread. PM core ensures all power state transition dependency between devices. This patch enables mmc hosts to suspend/resume asynchronously. This will take advantage of multicore and improve system suspend/resume speed. After applying this patch and enabling all mmc hosts' child devices to suspend/resume asynchronously on ASUS T100TA, the system suspend-to-idle time is reduced from 1645ms to 1107ms, and the system resume time is reduced from 940ms to 914ms.

Signed-off-by Zhonghui Fu <[email protected]>

---
 drivers/mmc/core/host.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

drivers/mmc/core/host.c +1 -1

index da950c4..7222fd7 100644
@@ -339,6 +339,7 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
 	host->class_dev.parent = dev;
 	host->class_dev.class = &mmc_host_class;
 	device_initialize(&host->class_dev);
+	device_enable_async_suspend(&host->class_dev);
 
 	if (mmc_gpio_alloc(host)) {
 		put_device(&host->class_dev);
-- 1.7.1

Now, PM core supports asynchronous suspend/resume mode for devices during system suspend/resume, and the power state transition of one device may be completed in separate kernel thread. PM core ensures all power state transition dependency between devices. This patch enables mmc hosts to suspend/resume asynchronously. This will take advantage of multicore and improve system suspend/resume speed. After applying this patch and enabling all mmc hosts' child devices to suspend/resume asynchronously on ASUS T100TA, the system suspend-to-idle time is reduced from 1645ms to 1107ms, and the system resume time is reduced from 940ms to 914ms.

Signed-off-by Zhonghui Fu <[email protected]>

---
 drivers/mmc/core/host.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

drivers/mmc/core/host.c +0 -0

index da950c4..7222fd7 100644

Quoted 10 lines · Zhonghui

Now, PM core supports asynchronous suspend/resume mode for devices during system suspend/resume, and the power state transition of one device may be completed in separate kernel thread. PM core ensures all power state transition dependency between devices. This patch enables mmc hosts to suspend/resume asynchronously. This will take advantage of multicore and improve system suspend/resume speed. After applying this patch and enabling all mmc hosts' child devices to suspend/resume asynchronously on ASUS T100TA, the system suspend-to-idle time is reduced from 1645ms to 1107ms, and the system resume time is reduced from 940ms to 914ms.

Please update the change log as I don't think the above is really correct.

I think you can simplify the change log quite a bit and just mention what and why we want this change.

Quoted 12 lines

Signed-off-by Zhonghui Fu <[email protected]>

---
 drivers/mmc/core/host.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

drivers/mmc/core/host.c +0 -0

index da950c4..7222fd7 100644

drivers/mmc/core/host.c struct mmc_host *mmc_alloc_host(int extra, struct device *dev)

Quoted 8 lines

drivers/mmc/core/host.c +1 -1

@@ -339,6 +339,7 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
        host->class_dev.parent = dev;
        host->class_dev.class = &mmc_host_class;
        device_initialize(&host->class_dev);
+       device_enable_async_suspend(&host->class_dev);
 
        if (mmc_gpio_alloc(host)) {
                put_device(&host->class_dev);
-- 1.7.1

Otherwise I think this looks good!

Kind regards
Uffe