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linux-stable/drivers/acpi/internal.h
Lv Zheng 74443bbed7 ACPI / EC: Fix issues related to the SCI_EVT handling 
This patch fixes 2 issues related to the draining behavior. But it doesn't
implement the draining support, it only cleans up code so that further
draining support is possible.

The draining behavior is expected by some platforms (for example, Samsung)
where SCI_EVT is set only once for a set of events and might be cleared for
the very first QR_EC command issued after SCI_EVT is set. EC firmware on
such platforms will return 0x00 to indicate "no outstanding event". Thus
after seeing an SCI_EVT indication, EC driver need to fetch events until
0x00 returned (see acpi_ec_clear()).

Issue 1 - acpi_ec_submit_query():
It's reported on Samsung laptops that SCI_EVT isn't checked when the
transactions are advanced in ec_poll(), which leads to SCI_EVT triggering
source lost:
 If no EC GPE IRQs are arrived after that, EC driver cannot detect this
 event and handle it.
See comment 244/247 for kernel bugzilla 44161.
This patch fixes this issue by moving SCI_EVT checks into
advance_transaction(). So that SCI_EVT is checked each time we are going to
handle the EC firmware indications. And this check will happen for both IRQ
context and task context.
Since after doing that, SCI_EVT is also checked after completing a
transaction, ec_check_sci() and ec_check_sci_sync() can be removed.

Issue 2 - acpi_ec_complete_query():
We expect to clear EC_FLAGS_QUERY_PENDING to allow queuing another draining
QR_EC after writing a QR_EC command and before reading the event. After
reading the event, SCI_EVT might be cleared by the firmware, thus it may
not be possible to queue such a draining QR_EC at that time.
But putting the EC_FLAGS_QUERY_PENDING clearing code after
start_transaction() is wrong as there are chances that after
start_transaction(), QR_EC can fail to be sent. If this happens,
EC_FLAG_QUERY_PENDING will be cleared earlier. As a consequence, the
draining QR_EC will also be queued earlier than expected.
This patch also moves this code into advance_transaction() where QR_EC is
just sent (ACPI_EC_COMMAND_POLL flagged) to fix this issue.

Notes:
1. After introducing the 2 SCI_EVT related handlings into
   advance_transaction(), a next QR_EC can be queued right after writing
   the current QR_EC command and before reading the event. But this still
   hasn't implemented the draining behavior as the draining support
   requires:
     If a previous returned event value isn't 0x00, a draining QR_EC need
     to be issued even when SCI_EVT isn't set.
2. In this patch, acpi_os_execute() is also converted into a seperate work
   item to avoid invoking kmalloc() in the atomic context. We can do this
   because of the previous global lock fix.
3. Originally, EC_FLAGS_EVENT_PENDING is also used to avoid queuing up
   multiple work items (created by acpi_os_execute()), this can be covered
   by only using a single work item. But this patch still keeps this flag
   as there are different usages in the driver initialization steps relying
   on this flag.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=44161
Reported-by: Kieran Clancy <clancy.kieran@gmail.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-01-23 22:06:49 +01:00

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/*
* acpi/internal.h
* For use by Linux/ACPI infrastructure, not drivers
*
* Copyright (c) 2009, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef _ACPI_INTERNAL_H_
#define _ACPI_INTERNAL_H_
#define PREFIX "ACPI: "
acpi_status acpi_os_initialize1(void);
int init_acpi_device_notify(void);
int acpi_scan_init(void);
void acpi_pci_root_init(void);
void acpi_pci_link_init(void);
void acpi_processor_init(void);
void acpi_platform_init(void);
void acpi_pnp_init(void);
void acpi_int340x_thermal_init(void);
int acpi_sysfs_init(void);
void acpi_container_init(void);
void acpi_memory_hotplug_init(void);
#ifdef CONFIG_ACPI_DOCK
void register_dock_dependent_device(struct acpi_device *adev,
acpi_handle dshandle);
int dock_notify(struct acpi_device *adev, u32 event);
void acpi_dock_add(struct acpi_device *adev);
#else
static inline void register_dock_dependent_device(struct acpi_device *adev,
acpi_handle dshandle) {}
static inline int dock_notify(struct acpi_device *adev, u32 event) { return -ENODEV; }
static inline void acpi_dock_add(struct acpi_device *adev) {}
#endif
#ifdef CONFIG_X86
void acpi_cmos_rtc_init(void);
#else
static inline void acpi_cmos_rtc_init(void) {}
#endif
extern bool acpi_force_hot_remove;
void acpi_sysfs_add_hotplug_profile(struct acpi_hotplug_profile *hotplug,
const char *name);
int acpi_scan_add_handler_with_hotplug(struct acpi_scan_handler *handler,
const char *hotplug_profile_name);
void acpi_scan_hotplug_enabled(struct acpi_hotplug_profile *hotplug, bool val);
#ifdef CONFIG_DEBUG_FS
extern struct dentry *acpi_debugfs_dir;
int acpi_debugfs_init(void);
#else
static inline void acpi_debugfs_init(void) { return; }
#endif
void acpi_lpss_init(void);
acpi_status acpi_hotplug_schedule(struct acpi_device *adev, u32 src);
bool acpi_queue_hotplug_work(struct work_struct *work);
void acpi_device_hotplug(struct acpi_device *adev, u32 src);
bool acpi_scan_is_offline(struct acpi_device *adev, bool uevent);
/* --------------------------------------------------------------------------
Device Node Initialization / Removal
-------------------------------------------------------------------------- */
#define ACPI_STA_DEFAULT (ACPI_STA_DEVICE_PRESENT | ACPI_STA_DEVICE_ENABLED | \
ACPI_STA_DEVICE_UI | ACPI_STA_DEVICE_FUNCTIONING)
int acpi_device_add(struct acpi_device *device,
void (*release)(struct device *));
void acpi_init_device_object(struct acpi_device *device, acpi_handle handle,
int type, unsigned long long sta);
void acpi_device_add_finalize(struct acpi_device *device);
void acpi_free_pnp_ids(struct acpi_device_pnp *pnp);
bool acpi_device_is_present(struct acpi_device *adev);
bool acpi_device_is_battery(struct acpi_device *adev);
/* --------------------------------------------------------------------------
Power Resource
-------------------------------------------------------------------------- */
int acpi_power_init(void);
void acpi_power_resources_list_free(struct list_head *list);
int acpi_extract_power_resources(union acpi_object *package, unsigned int start,
struct list_head *list);
int acpi_add_power_resource(acpi_handle handle);
void acpi_power_add_remove_device(struct acpi_device *adev, bool add);
int acpi_power_wakeup_list_init(struct list_head *list, int *system_level);
int acpi_device_sleep_wake(struct acpi_device *dev,
int enable, int sleep_state, int dev_state);
int acpi_power_get_inferred_state(struct acpi_device *device, int *state);
int acpi_power_on_resources(struct acpi_device *device, int state);
int acpi_power_transition(struct acpi_device *device, int state);
int acpi_wakeup_device_init(void);
#ifdef CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC
void acpi_early_processor_set_pdc(void);
#else
static inline void acpi_early_processor_set_pdc(void) {}
#endif
/* --------------------------------------------------------------------------
Embedded Controller
-------------------------------------------------------------------------- */
struct acpi_ec {
acpi_handle handle;
unsigned long gpe;
unsigned long command_addr;
unsigned long data_addr;
unsigned long global_lock;
unsigned long flags;
struct mutex mutex;
wait_queue_head_t wait;
struct list_head list;
struct transaction *curr;
spinlock_t lock;
struct work_struct work;
};
extern struct acpi_ec *first_ec;
/* If we find an EC via the ECDT, we need to keep a ptr to its context */
/* External interfaces use first EC only, so remember */
typedef int (*acpi_ec_query_func) (void *data);
int acpi_ec_init(void);
int acpi_ec_ecdt_probe(void);
int acpi_boot_ec_enable(void);
void acpi_ec_block_transactions(void);
void acpi_ec_unblock_transactions(void);
void acpi_ec_unblock_transactions_early(void);
int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
acpi_handle handle, acpi_ec_query_func func,
void *data);
void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
/*--------------------------------------------------------------------------
Suspend/Resume
-------------------------------------------------------------------------- */
extern int acpi_sleep_init(void);
#ifdef CONFIG_ACPI_SLEEP
int acpi_sleep_proc_init(void);
int suspend_nvs_alloc(void);
void suspend_nvs_free(void);
int suspend_nvs_save(void);
void suspend_nvs_restore(void);
#else
static inline int acpi_sleep_proc_init(void) { return 0; }
static inline int suspend_nvs_alloc(void) { return 0; }
static inline void suspend_nvs_free(void) {}
static inline int suspend_nvs_save(void) { return 0; }
static inline void suspend_nvs_restore(void) {}
#endif
/*--------------------------------------------------------------------------
Video
-------------------------------------------------------------------------- */
#if defined(CONFIG_ACPI_VIDEO) || defined(CONFIG_ACPI_VIDEO_MODULE)
bool acpi_osi_is_win8(void);
#endif
/*--------------------------------------------------------------------------
Device properties
-------------------------------------------------------------------------- */
void acpi_init_properties(struct acpi_device *adev);
void acpi_free_properties(struct acpi_device *adev);
#endif /* _ACPI_INTERNAL_H_ */
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