Commit b52fb259 authored by Ulf Hansson's avatar Ulf Hansson
Browse files

mmc: core: Always allow the card detect uevent to be consumed 



The approach to allow userspace ~5s to consume the uevent, which is
triggered when a new card is inserted/initialized, currently requires the
mmc host to support system wakeup.

This is unnecessary limiting, especially for an mmc host that relies on a
GPIO IRQ for card detect. More precisely, the mmc host may not support
system wakeup for its corresponding struct device, while the GPIO IRQ still
could be configured as a wakeup IRQ via enable_irq_wake().

To support all various cases, let's simply drop the need for the wakeup
support. Instead let's always register a wakeup source and activate it for
all card detect IRQs by calling __pm_wakeup_event().

Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20200529102341.12529-1-ulf.hansson@linaro.org
parent 11ba4688

drivers/mmc/core/core.c

+5 −5
Original line number Diff line number Diff line
@@ -1455,12 +1455,12 @@ void mmc_detach_bus(struct mmc_host *host) 
void _mmc_detect_change(struct mmc_host *host, unsigned long delay, bool cd_irq)

{

	/*

	 * If the device is configured as wakeup, we prevent a new sleep for

	 * 5 s to give provision for user space to consume the event.

	 * Prevent system sleep for 5s to allow user space to consume the

	 * corresponding uevent. This is especially useful, when CD irq is used

	 * as a system wakeup, but doesn't hurt in other cases.

	 */

	if (cd_irq && !(host->caps & MMC_CAP_NEEDS_POLL) &&

		device_can_wakeup(mmc_dev(host)))

		pm_wakeup_event(mmc_dev(host), 5000);

	if (cd_irq && !(host->caps & MMC_CAP_NEEDS_POLL))

		__pm_wakeup_event(host->ws, 5000);



	host->detect_change = 1;

	mmc_schedule_delayed_work(&host->detect, delay);

drivers/mmc/core/host.c

+3 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/of.h>

#include <linux/of_gpio.h>

#include <linux/pagemap.h>

#include <linux/pm_wakeup.h>

#include <linux/export.h>

#include <linux/leds.h>

#include <linux/slab.h>
@@ -36,6 +37,7 @@ static DEFINE_IDA(mmc_host_ida); 
static void mmc_host_classdev_release(struct device *dev)

{

	struct mmc_host *host = cls_dev_to_mmc_host(dev);

	wakeup_source_unregister(host->ws);

	ida_simple_remove(&mmc_host_ida, host->index);

	kfree(host);

}
@@ -400,6 +402,7 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev) 
	host->index = err;



	dev_set_name(&host->class_dev, "mmc%d", host->index);

	host->ws = wakeup_source_register(NULL, dev_name(&host->class_dev));



	host->parent = dev;

	host->class_dev.parent = dev;

include/linux/mmc/host.h

+1 −0
Original line number Diff line number Diff line
@@ -287,6 +287,7 @@ struct mmc_host { 
#ifdef CONFIG_PM_SLEEP

	struct notifier_block	pm_notify;

#endif

	struct wakeup_source	*ws;		/* Enable consume of uevents */

	u32			max_current_330;

	u32			max_current_300;

	u32			max_current_180;