From: Alexey Starikovskiy <astarikovskiy@xxxxxxx> Split EC query handling into acknowledge and execution phase. This allows much smaller pending query lattency and lowers chances of EC going "wild" and losing events. Reference: http://bugzilla.kernel.org/show_bug.cgi?id=14858 Signed-off-by: Alexey Starikovskiy <astarikovskiy@xxxxxxx> Signed-off-by: Len Brown <len.brown@xxxxxxxxx> --- drivers/acpi/ec.c | 122 +++++++++++++++++++++++++++++++++------------------- 1 files changed, 77 insertions(+), 45 deletions(-) diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index fd1801b..9cc3885 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -201,14 +201,13 @@ unlock: spin_unlock_irqrestore(&ec->curr_lock, flags); } -static void acpi_ec_gpe_query(void *ec_cxt); +static int acpi_ec_sync_query(struct acpi_ec *ec); -static int ec_check_sci(struct acpi_ec *ec, u8 state) +static int ec_check_sci_sync(struct acpi_ec *ec, u8 state) { if (state & ACPI_EC_FLAG_SCI) { if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) - return acpi_os_execute(OSL_EC_BURST_HANDLER, - acpi_ec_gpe_query, ec); + return acpi_ec_sync_query(ec); } return 0; } @@ -249,11 +248,6 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, { unsigned long tmp; int ret = 0; - pr_debug(PREFIX "transaction start\n"); - /* disable GPE during transaction if storm is detected */ - if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) { - acpi_disable_gpe(NULL, ec->gpe); - } if (EC_FLAGS_MSI) udelay(ACPI_EC_MSI_UDELAY); /* start transaction */ @@ -269,16 +263,6 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, spin_lock_irqsave(&ec->curr_lock, tmp); ec->curr = NULL; spin_unlock_irqrestore(&ec->curr_lock, tmp); - if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) { - /* check if we received SCI during transaction */ - ec_check_sci(ec, acpi_ec_read_status(ec)); - /* it is safe to enable GPE outside of transaction */ - acpi_enable_gpe(NULL, ec->gpe); - } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) { - pr_info(PREFIX "GPE storm detected, " - "transactions will use polling mode\n"); - set_bit(EC_FLAGS_GPE_STORM, &ec->flags); - } return ret; } @@ -321,7 +305,24 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t) status = -ETIME; goto end; } + pr_debug(PREFIX "transaction start\n"); + /* disable GPE during transaction if storm is detected */ + if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) { + acpi_disable_gpe(NULL, ec->gpe); + } + status = acpi_ec_transaction_unlocked(ec, t); + + /* check if we received SCI during transaction */ + ec_check_sci_sync(ec, acpi_ec_read_status(ec)); + if (test_bit(EC_FLAGS_GPE_STORM, &ec->flags)) { + /* it is safe to enable GPE outside of transaction */ + acpi_enable_gpe(NULL, ec->gpe); + } else if (t->irq_count > ACPI_EC_STORM_THRESHOLD) { + pr_info(PREFIX "GPE storm detected, " + "transactions will use polling mode\n"); + set_bit(EC_FLAGS_GPE_STORM, &ec->flags); + } end: if (ec->global_lock) acpi_release_global_lock(glk); @@ -443,7 +444,7 @@ int ec_transaction(u8 command, EXPORT_SYMBOL(ec_transaction); -static int acpi_ec_query(struct acpi_ec *ec, u8 * data) +static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 * data) { int result; u8 d; @@ -452,20 +453,16 @@ static int acpi_ec_query(struct acpi_ec *ec, u8 * data) .wlen = 0, .rlen = 1}; if (!ec || !data) return -EINVAL; - /* * Query the EC to find out which _Qxx method we need to evaluate. * Note that successful completion of the query causes the ACPI_EC_SCI * bit to be cleared (and thus clearing the interrupt source). */ - - result = acpi_ec_transaction(ec, &t); + result = acpi_ec_transaction_unlocked(ec, &t); if (result) return result; - if (!d) return -ENODATA; - *data = d; return 0; } @@ -509,43 +506,78 @@ void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit) EXPORT_SYMBOL_GPL(acpi_ec_remove_query_handler); -static void acpi_ec_gpe_query(void *ec_cxt) +static void acpi_ec_run(void *cxt) { - struct acpi_ec *ec = ec_cxt; - u8 value = 0; - struct acpi_ec_query_handler *handler, copy; - - if (!ec || acpi_ec_query(ec, &value)) + struct acpi_ec_query_handler *handler = cxt; + if (!handler) return; - mutex_lock(&ec->lock); + pr_debug(PREFIX "start query execution\n"); + if (handler->func) + handler->func(handler->data); + else if (handler->handle) + acpi_evaluate_object(handler->handle, NULL, NULL, NULL); + pr_debug(PREFIX "stop query execution\n"); + kfree(handler); +} + +static int acpi_ec_sync_query(struct acpi_ec *ec) +{ + u8 value = 0; + int status; + struct acpi_ec_query_handler *handler, *copy; + if ((status = acpi_ec_query_unlocked(ec, &value))) + return status; list_for_each_entry(handler, &ec->list, node) { if (value == handler->query_bit) { /* have custom handler for this bit */ - memcpy(©, handler, sizeof(copy)); - mutex_unlock(&ec->lock); - if (copy.func) { - copy.func(copy.data); - } else if (copy.handle) { - acpi_evaluate_object(copy.handle, NULL, NULL, NULL); - } - return; + copy = kmalloc(sizeof(*handler), GFP_KERNEL); + if (!copy) + return -ENOMEM; + memcpy(copy, handler, sizeof(*copy)); + pr_debug(PREFIX "push query execution (0x%2x) on queue\n", value); + return acpi_os_execute(OSL_GPE_HANDLER, + acpi_ec_run, copy); } } + return 0; +} + +static void acpi_ec_gpe_query(void *ec_cxt) +{ + struct acpi_ec *ec = ec_cxt; + if (!ec) + return; + mutex_lock(&ec->lock); + acpi_ec_sync_query(ec); mutex_unlock(&ec->lock); } +static void acpi_ec_gpe_query(void *ec_cxt); + +static int ec_check_sci(struct acpi_ec *ec, u8 state) +{ + if (state & ACPI_EC_FLAG_SCI) { + if (!test_and_set_bit(EC_FLAGS_QUERY_PENDING, &ec->flags)) { + pr_debug(PREFIX "push gpe query to the queue\n"); + return acpi_os_execute(OSL_NOTIFY_HANDLER, + acpi_ec_gpe_query, ec); + } + } + return 0; +} + static u32 acpi_ec_gpe_handler(void *data) { struct acpi_ec *ec = data; - u8 status; pr_debug(PREFIX "~~~> interrupt\n"); - status = acpi_ec_read_status(ec); - advance_transaction(ec, status); - if (ec_transaction_done(ec) && (status & ACPI_EC_FLAG_IBF) == 0) + advance_transaction(ec, acpi_ec_read_status(ec)); + if (ec_transaction_done(ec) && + (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) { wake_up(&ec->wait); - ec_check_sci(ec, status); + ec_check_sci(ec, acpi_ec_read_status(ec)); + } return ACPI_INTERRUPT_HANDLED; } -- 1.6.0.6 -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
