From: Lv Zheng <lv.zheng@intel.com> To: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>, Len Brown <len.brown@intel.com> Cc: Lv Zheng <lv.zheng@intel.com>, Lv Zheng <zetalog@gmail.com>, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org Subject: [PATCH v2 2/5] ACPI / EC: Add command flushing support. Date: Fri, 6 Feb 2015 08:57:59 +0800 [thread overview] Message-ID: <991bf8b675e1a0a04ddf3af8d8dd792239ffef03.1423183648.git.lv.zheng@intel.com> (raw) In-Reply-To: <cover.1423183647.git.lv.zheng@intel.com> This patch implements the EC command flushing support. During the grace period indicated by EC_FLAGS_STARTED and EC_FLAGS_STOPPED, all submitted EC command transactions can be completed and new submissions are prevented before suspending so that the EC hardware can be ensured to be in the idle state when the system is resumed. There is a good indicator for flush support: All acpi_ec_submit_request() is invoked after checking driver state with acpi_ec_started() except the first one. This means all code paths can be flushed as fast as possible by discarding the requests occurred after the flush operation. The reference increased for such kind of code path is wrapped by acpi_ec_submit_flushable_request(). Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Ortwin Glück <odi@odi.ch> --- drivers/acpi/ec.c | 68 ++++++++++++++++++++++++++++++++++++++++++++--- drivers/acpi/internal.h | 1 + 2 files changed, 66 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index a6179b7..1fa1463 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -145,6 +145,11 @@ static bool acpi_ec_started(struct acpi_ec *ec) !test_bit(EC_FLAGS_STOPPED, &ec->flags); } +static bool acpi_ec_flushed(struct acpi_ec *ec) +{ + return ec->reference_count == 1; +} + /* -------------------------------------------------------------------------- * EC Registers * -------------------------------------------------------------------------- */ @@ -266,6 +271,44 @@ static inline void acpi_ec_clear_gpe(struct acpi_ec *ec) * Transaction Management * -------------------------------------------------------------------------- */ +static void acpi_ec_submit_request(struct acpi_ec *ec) +{ + ec->reference_count++; + if (ec->reference_count == 1) + acpi_ec_enable_gpe(ec, true); +} + +static void acpi_ec_complete_request(struct acpi_ec *ec) +{ + bool flushed = false; + + ec->reference_count--; + if (ec->reference_count == 0) + acpi_ec_disable_gpe(ec, true); + flushed = acpi_ec_flushed(ec); + if (flushed) + wake_up(&ec->wait); +} + +/* + * acpi_ec_submit_flushable_request() - Increase the reference count unless + * the flush operation is not in + * progress + * @ec: the EC device + * + * This function must be used before taking a new action that should hold + * the reference count. If this function returns false, then the action + * must be discarded or it will prevent the flush operation from being + * completed. + */ +static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec) +{ + if (!acpi_ec_started(ec)) + return false; + acpi_ec_submit_request(ec); + return true; +} + static void acpi_ec_submit_query(struct acpi_ec *ec) { if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { @@ -426,7 +469,8 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, udelay(ACPI_EC_MSI_UDELAY); /* start transaction */ spin_lock_irqsave(&ec->lock, tmp); - if (!acpi_ec_started(ec)) { + /* Enable GPE for command processing (IBF=0/OBF=1) */ + if (!acpi_ec_submit_flushable_request(ec)) { ret = -EINVAL; goto unlock; } @@ -441,6 +485,8 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, pr_debug("***** Command(%s) stopped *****\n", acpi_ec_cmd_string(t->command)); ec->curr = NULL; + /* Disable GPE for command processing (IBF=0/OBF=1) */ + acpi_ec_complete_request(ec); unlock: spin_unlock_irqrestore(&ec->lock, tmp); return ret; @@ -614,13 +660,25 @@ static void acpi_ec_start(struct acpi_ec *ec, bool resuming) spin_lock_irqsave(&ec->lock, flags); if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) { pr_debug("+++++ Starting EC +++++\n"); + /* Enable GPE for event processing (SCI_EVT=1) */ if (!resuming) - acpi_ec_enable_gpe(ec, true); + acpi_ec_submit_request(ec); pr_info("+++++ EC started +++++\n"); } spin_unlock_irqrestore(&ec->lock, flags); } +static bool acpi_ec_stopped(struct acpi_ec *ec) +{ + unsigned long flags; + bool flushed; + + spin_lock_irqsave(&ec->lock, flags); + flushed = acpi_ec_flushed(ec); + spin_unlock_irqrestore(&ec->lock, flags); + return flushed; +} + static void acpi_ec_stop(struct acpi_ec *ec, bool suspending) { unsigned long flags; @@ -629,8 +687,12 @@ static void acpi_ec_stop(struct acpi_ec *ec, bool suspending) if (acpi_ec_started(ec)) { pr_debug("+++++ Stopping EC +++++\n"); set_bit(EC_FLAGS_STOPPED, &ec->flags); + spin_unlock_irqrestore(&ec->lock, flags); + wait_event(ec->wait, acpi_ec_stopped(ec)); + spin_lock_irqsave(&ec->lock, flags); + /* Disable GPE for event processing (SCI_EVT=1) */ if (!suspending) - acpi_ec_disable_gpe(ec, true); + acpi_ec_complete_request(ec); clear_bit(EC_FLAGS_STARTED, &ec->flags); clear_bit(EC_FLAGS_STOPPED, &ec->flags); pr_info("+++++ EC stopped +++++\n"); diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 63e3495..6a4420d 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -129,6 +129,7 @@ struct acpi_ec { 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; -- 1.7.10
WARNING: multiple messages have this Message-ID (diff)
From: Lv Zheng <lv.zheng@intel.com> To: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>, Len Brown <len.brown@intel.com> Cc: Lv Zheng <lv.zheng@intel.com>, Lv Zheng <zetalog@gmail.com>, <linux-kernel@vger.kernel.org>, linux-acpi@vger.kernel.org Subject: [PATCH v2 2/5] ACPI / EC: Add command flushing support. Date: Fri, 6 Feb 2015 08:57:59 +0800 [thread overview] Message-ID: <991bf8b675e1a0a04ddf3af8d8dd792239ffef03.1423183648.git.lv.zheng@intel.com> (raw) In-Reply-To: <cover.1423183647.git.lv.zheng@intel.com> This patch implements the EC command flushing support. During the grace period indicated by EC_FLAGS_STARTED and EC_FLAGS_STOPPED, all submitted EC command transactions can be completed and new submissions are prevented before suspending so that the EC hardware can be ensured to be in the idle state when the system is resumed. There is a good indicator for flush support: All acpi_ec_submit_request() is invoked after checking driver state with acpi_ec_started() except the first one. This means all code paths can be flushed as fast as possible by discarding the requests occurred after the flush operation. The reference increased for such kind of code path is wrapped by acpi_ec_submit_flushable_request(). Signed-off-by: Lv Zheng <lv.zheng@intel.com> Tested-by: Ortwin Glück <odi@odi.ch> --- drivers/acpi/ec.c | 68 ++++++++++++++++++++++++++++++++++++++++++++--- drivers/acpi/internal.h | 1 + 2 files changed, 66 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index a6179b7..1fa1463 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -145,6 +145,11 @@ static bool acpi_ec_started(struct acpi_ec *ec) !test_bit(EC_FLAGS_STOPPED, &ec->flags); } +static bool acpi_ec_flushed(struct acpi_ec *ec) +{ + return ec->reference_count == 1; +} + /* -------------------------------------------------------------------------- * EC Registers * -------------------------------------------------------------------------- */ @@ -266,6 +271,44 @@ static inline void acpi_ec_clear_gpe(struct acpi_ec *ec) * Transaction Management * -------------------------------------------------------------------------- */ +static void acpi_ec_submit_request(struct acpi_ec *ec) +{ + ec->reference_count++; + if (ec->reference_count == 1) + acpi_ec_enable_gpe(ec, true); +} + +static void acpi_ec_complete_request(struct acpi_ec *ec) +{ + bool flushed = false; + + ec->reference_count--; + if (ec->reference_count == 0) + acpi_ec_disable_gpe(ec, true); + flushed = acpi_ec_flushed(ec); + if (flushed) + wake_up(&ec->wait); +} + +/* + * acpi_ec_submit_flushable_request() - Increase the reference count unless + * the flush operation is not in + * progress + * @ec: the EC device + * + * This function must be used before taking a new action that should hold + * the reference count. If this function returns false, then the action + * must be discarded or it will prevent the flush operation from being + * completed. + */ +static bool acpi_ec_submit_flushable_request(struct acpi_ec *ec) +{ + if (!acpi_ec_started(ec)) + return false; + acpi_ec_submit_request(ec); + return true; +} + static void acpi_ec_submit_query(struct acpi_ec *ec) { if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { @@ -426,7 +469,8 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, udelay(ACPI_EC_MSI_UDELAY); /* start transaction */ spin_lock_irqsave(&ec->lock, tmp); - if (!acpi_ec_started(ec)) { + /* Enable GPE for command processing (IBF=0/OBF=1) */ + if (!acpi_ec_submit_flushable_request(ec)) { ret = -EINVAL; goto unlock; } @@ -441,6 +485,8 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, pr_debug("***** Command(%s) stopped *****\n", acpi_ec_cmd_string(t->command)); ec->curr = NULL; + /* Disable GPE for command processing (IBF=0/OBF=1) */ + acpi_ec_complete_request(ec); unlock: spin_unlock_irqrestore(&ec->lock, tmp); return ret; @@ -614,13 +660,25 @@ static void acpi_ec_start(struct acpi_ec *ec, bool resuming) spin_lock_irqsave(&ec->lock, flags); if (!test_and_set_bit(EC_FLAGS_STARTED, &ec->flags)) { pr_debug("+++++ Starting EC +++++\n"); + /* Enable GPE for event processing (SCI_EVT=1) */ if (!resuming) - acpi_ec_enable_gpe(ec, true); + acpi_ec_submit_request(ec); pr_info("+++++ EC started +++++\n"); } spin_unlock_irqrestore(&ec->lock, flags); } +static bool acpi_ec_stopped(struct acpi_ec *ec) +{ + unsigned long flags; + bool flushed; + + spin_lock_irqsave(&ec->lock, flags); + flushed = acpi_ec_flushed(ec); + spin_unlock_irqrestore(&ec->lock, flags); + return flushed; +} + static void acpi_ec_stop(struct acpi_ec *ec, bool suspending) { unsigned long flags; @@ -629,8 +687,12 @@ static void acpi_ec_stop(struct acpi_ec *ec, bool suspending) if (acpi_ec_started(ec)) { pr_debug("+++++ Stopping EC +++++\n"); set_bit(EC_FLAGS_STOPPED, &ec->flags); + spin_unlock_irqrestore(&ec->lock, flags); + wait_event(ec->wait, acpi_ec_stopped(ec)); + spin_lock_irqsave(&ec->lock, flags); + /* Disable GPE for event processing (SCI_EVT=1) */ if (!suspending) - acpi_ec_disable_gpe(ec, true); + acpi_ec_complete_request(ec); clear_bit(EC_FLAGS_STARTED, &ec->flags); clear_bit(EC_FLAGS_STOPPED, &ec->flags); pr_info("+++++ EC stopped +++++\n"); diff --git a/drivers/acpi/internal.h b/drivers/acpi/internal.h index 63e3495..6a4420d 100644 --- a/drivers/acpi/internal.h +++ b/drivers/acpi/internal.h @@ -129,6 +129,7 @@ struct acpi_ec { 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; -- 1.7.10
next prev parent reply other threads:[~2015-02-06 0:57 UTC|newest] Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-11-03 5:16 [PATCH 0/6] ACPI/EC: Cleanups of command flushing and event polling Lv Zheng 2014-11-03 5:16 ` Lv Zheng 2014-11-03 5:16 ` [PATCH 1/6] ACPI/EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag Lv Zheng 2014-11-03 5:16 ` Lv Zheng 2014-11-05 2:52 ` Zheng, Lv 2014-11-05 2:52 ` Zheng, Lv 2014-11-18 13:23 ` Kirill A. Shutemov 2014-11-18 21:20 ` Rafael J. Wysocki 2014-11-19 8:55 ` Zheng, Lv 2014-11-19 8:55 ` Zheng, Lv 2014-11-19 12:16 ` Kirill A. Shutemov 2014-11-20 2:19 ` [RFC PATCH v3 1/2] ACPICA: Events: Remove duplicated sanity check in acpi_ev_enable_gpe() Lv Zheng 2014-11-20 2:19 ` Lv Zheng 2014-11-20 2:19 ` [RFC PATCH v3 2/2] ACPICA: Events: Introduce ACPI_GPE_HANDLER_RAW to fix 2 issues for the current GPE APIs Lv Zheng 2014-11-20 2:19 ` Lv Zheng 2014-11-20 2:20 ` [PATCH 1/6] ACPI/EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag Zheng, Lv 2014-11-20 21:33 ` Kirill A. Shutemov 2014-11-21 0:42 ` Zheng, Lv 2014-11-21 0:55 ` Zheng, Lv 2014-11-20 2:34 ` Zheng, Lv 2014-11-20 21:34 ` Kirill A. Shutemov 2014-11-20 6:44 ` [RFC PATCH v4] ACPICA/Events: Add support to ensure GPE is disabled by default for handlers Lv Zheng 2014-11-20 6:44 ` Lv Zheng 2014-11-20 6:47 ` Zheng, Lv 2014-11-20 22:15 ` Kirill A. Shutemov 2014-11-21 1:36 ` Zheng, Lv 2015-02-06 0:57 ` [PATCH v2 0/5] ACPI / EC: Add reference counting for requests and cleans up the grace periods support Lv Zheng 2015-02-06 0:57 ` Lv Zheng 2015-02-06 0:57 ` [PATCH v2 1/5] ACPI / EC: Introduce STARTED/STOPPED flags to replace BLOCKED flag Lv Zheng 2015-02-06 0:57 ` Lv Zheng 2015-02-06 0:57 ` Lv Zheng [this message] 2015-02-06 0:57 ` [PATCH v2 2/5] ACPI / EC: Add command flushing support Lv Zheng 2015-02-06 0:58 ` [PATCH v2 3/5] ACPI / EC: Refine command storm prevention support Lv Zheng 2015-02-06 0:58 ` Lv Zheng 2015-02-06 0:58 ` [PATCH v2 4/5] ACPI / EC: Add query flushing support Lv Zheng 2015-02-06 0:58 ` Lv Zheng 2015-02-06 0:58 ` [PATCH v2 5/5] ACPI / EC: Add GPE reference counting debugging messages Lv Zheng 2015-02-06 0:58 ` Lv Zheng 2015-02-06 1:26 ` [PATCH v2 0/5] ACPI / EC: Add reference counting for requests and cleans up the grace periods support Rafael J. Wysocki 2015-02-09 2:23 ` Zheng, Lv 2015-02-09 2:23 ` Zheng, Lv 2015-02-12 1:17 ` Rafael J. Wysocki 2015-02-16 6:41 ` Zheng, Lv 2015-02-16 6:41 ` Zheng, Lv 2014-11-03 5:16 ` [PATCH 2/6] ACPI/EC: Enhance the checks to apply to QR_EC transactions Lv Zheng 2014-11-03 5:16 ` Lv Zheng 2014-11-03 5:16 ` [PATCH 3/6] ACPI/EC: Add reference counting for query handlers Lv Zheng 2014-11-03 5:16 ` Lv Zheng 2014-11-03 5:16 ` [PATCH 4/6] ACPI/EC: Add command flushing support Lv Zheng 2014-11-03 5:16 ` Lv Zheng 2014-11-03 5:16 ` [PATCH 5/6] ACPI/EC: Cleanup QR_SC command processing by adding a kernel thread to poll EC events Lv Zheng 2014-11-03 5:16 ` Lv Zheng 2014-11-12 1:16 ` Rafael J. Wysocki 2014-11-12 1:16 ` Rafael J. Wysocki 2014-11-13 2:31 ` Zheng, Lv 2014-11-13 2:31 ` Zheng, Lv 2014-11-13 2:58 ` Rafael J. Wysocki 2014-11-13 2:52 ` Zheng, Lv 2014-11-13 2:52 ` Zheng, Lv 2014-11-13 22:37 ` Rafael J. Wysocki 2014-11-14 1:21 ` Zheng, Lv 2014-11-14 1:21 ` Zheng, Lv 2014-11-14 23:38 ` Rafael J. Wysocki 2014-11-03 5:16 ` [PATCH 6/6] ACPI/EC: Add GPE reference counting debugging messages Lv Zheng 2014-11-03 5:16 ` Lv Zheng
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