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linux-next/drivers/acpi/internal.h
Lv Zheng d8d031a605 ACPI / EC: Fix and clean up register access guarding logics.
In the polling mode, EC driver shouldn't access the EC registers too
frequently. Though this statement is concluded from the non-root caused
bugs (see links below), we've maintained the register access guarding
logics in the current EC driver. The guarding logics can be found here and
there, makes it hard to root cause real timing issues. This patch collects
the guarding logics into one single function so that all hidden logics
related to this can be seen clearly.

The current guarding related code also has several issues:
1. Per-transaction timestamp prevents inter-transaction guarding from being
   implemented in the same place. We have an inter-transaction udelay() in
   acpi_ec_transaction_unblocked(), this logic can be merged into ec_poll()
   if we can use per-device timestamp. This patch completes such merge to
   form a new ec_guard() function and collects all guarding related hidden
   logics in it.
   One hidden logic is: there is no inter-transaction guarding performed
   for non MSI quirk (wait polling mode), this patch skips
   inter-transaction guarding before wait_event_timeout() for the wait
   polling mode to reveal the hidden logic.
   The other hidden logic is: there is msleep() inter-transaction guarding
   performed when the GPE storming is observed. As after merging this
   commit:
     Commit: e1d4d90fc0
     Subject: ACPI / EC: Refine command storm prevention support
   EC_FLAGS_COMMAND_STORM is ensured to be cleared after invoking
   acpi_ec_transaction_unlocked(), the msleep() guard logic will never
   happen now. Since no one complains such change, this logic is likely
   added during the old times where the EC race issues are not fixed and
   the bugs are false root-caused to the timing issue. This patch simply
   removes the out-dated logic. We can restore it by stop skipping
   inter-transaction guarding for wait polling mode.
   Two different delay values are defined for msleep() and udelay() while
   they are merged in this patch to 550us.
2. time_after() causes additional delay in the polling mode (can only be
   observed in noirq suspend/resume processes where polling mode is always
   used) before advance_transaction() is invoked ("wait polling" log is
   added before wait_event_timeout()). We can see 2 wait_event_timeout()
   invocations. This is because time_after() ensures a ">" validation while
   we only need a ">=" validation here:
   [   86.739909] ACPI: Waking up from system sleep state S3
   [   86.742857] ACPI : EC: 2: Increase command
   [   86.742859] ACPI : EC: ***** Command(RD_EC) started *****
   [   86.742861] ACPI : EC: ===== TASK (0) =====
   [   86.742871] ACPI : EC: EC_SC(R) = 0x20 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=0
   [   86.742873] ACPI : EC: EC_SC(W) = 0x80
   [   86.742876] ACPI : EC: ***** Event started *****
   [   86.742880] ACPI : EC: ~~~~~ wait polling ~~~~~
   [   86.743972] ACPI : EC: ~~~~~ wait polling ~~~~~
   [   86.747966] ACPI : EC: ===== TASK (0) =====
   [   86.747977] ACPI : EC: EC_SC(R) = 0x20 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=0
   [   86.747978] ACPI : EC: EC_DATA(W) = 0x06
   [   86.747981] ACPI : EC: ~~~~~ wait polling ~~~~~
   [   86.751971] ACPI : EC: ~~~~~ wait polling ~~~~~
   [   86.755969] ACPI : EC: ===== TASK (0) =====
   [   86.755991] ACPI : EC: EC_SC(R) = 0x21 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=1
   [   86.755993] ACPI : EC: EC_DATA(R) = 0x03
   [   86.755994] ACPI : EC: ~~~~~ wait polling ~~~~~
   [   86.755995] ACPI : EC: ***** Command(RD_EC) stopped *****
   [   86.755996] ACPI : EC: 1: Decrease command
   This patch corrects this by using time_before() instead in ec_guard():
   [   54.283146] ACPI: Waking up from system sleep state S3
   [   54.285414] ACPI : EC: 2: Increase command
   [   54.285415] ACPI : EC: ***** Command(RD_EC) started *****
   [   54.285416] ACPI : EC: ~~~~~ wait polling ~~~~~
   [   54.285417] ACPI : EC: ===== TASK (0) =====
   [   54.285424] ACPI : EC: EC_SC(R) = 0x20 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=0
   [   54.285425] ACPI : EC: EC_SC(W) = 0x80
   [   54.285427] ACPI : EC: ***** Event started *****
   [   54.285429] ACPI : EC: ~~~~~ wait polling ~~~~~
   [   54.287209] ACPI : EC: ===== TASK (0) =====
   [   54.287218] ACPI : EC: EC_SC(R) = 0x20 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=0
   [   54.287219] ACPI : EC: EC_DATA(W) = 0x06
   [   54.287222] ACPI : EC: ~~~~~ wait polling ~~~~~
   [   54.291190] ACPI : EC: ===== TASK (0) =====
   [   54.291210] ACPI : EC: EC_SC(R) = 0x21 SCI_EVT=1 BURST=0 CMD=0 IBF=0 OBF=1
   [   54.291213] ACPI : EC: EC_DATA(R) = 0x03
   [   54.291214] ACPI : EC: ~~~~~ wait polling ~~~~~
   [   54.291215] ACPI : EC: ***** Command(RD_EC) stopped *****
   [   54.291216] ACPI : EC: 1: Decrease command

After cleaning up all guarding logics, we have one single function
ec_guard() collecting all old, non-root-caused, hidden logics. Then we can
easily tune the logics in one place to respond to the bug reports.

Except the time_before() change, all other changes do not change the
behavior of the EC driver.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=12011
Link: https://bugzilla.kernel.org/show_bug.cgi?id=20242
Link: https://bugzilla.kernel.org/show_bug.cgi?id=77431
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-16 01:51:18 +02:00

199 lines
7.3 KiB
C

/*
* 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_HOTPLUG_IOAPIC
int acpi_ioapic_add(struct acpi_pci_root *root);
int acpi_ioapic_remove(struct acpi_pci_root *root);
#else
static inline int acpi_ioapic_add(struct acpi_pci_root *root) { return 0; }
static inline int acpi_ioapic_remove(struct acpi_pci_root *root) { return 0; }
#endif
#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);
void acpi_apd_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;
unsigned long reference_count;
struct mutex mutex;
wait_queue_head_t wait;
struct list_head list;
struct transaction *curr;
spinlock_t lock;
struct work_struct work;
unsigned long timestamp;
};
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
-------------------------------------------------------------------------- */
#ifdef CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT
extern int acpi_sleep_init(void);
#else
static inline int acpi_sleep_init(void) { return -ENXIO; }
#endif
#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_ */