Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161192AbaGRNQ4 (ORCPT ); Fri, 18 Jul 2014 09:16:56 -0400 Received: from bband-dyn38.178-41-141.t-com.sk ([178.41.141.38]:17894 "EHLO ip4-83-240-18-248.cust.nbox.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S935179AbaGRNQw (ORCPT ); Fri, 18 Jul 2014 09:16:52 -0400 From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Lv Zheng , "Rafael J. Wysocki" , Jiri Slaby Subject: [PATCH 3.12 143/170] ACPI / EC: Remove duplicated ec_wait_ibf0() waiter Date: Fri, 18 Jul 2014 14:12:28 +0200 Message-Id: <8c7ffca7f2ad7dbb3bb3834d4de11725cce69b85.1405685481.git.jslaby@suse.cz> X-Mailer: git-send-email 2.0.0 In-Reply-To: <48e8cad86bb1241c08bdaa80db022c25068ff8e0.1405685481.git.jslaby@suse.cz> References: <48e8cad86bb1241c08bdaa80db022c25068ff8e0.1405685481.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lv Zheng 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 9b80f0f73ae1583c22325ede341c74195847618c upstream. After we've added the first command byte write into advance_transaction(), the IBF=0 waiter is duplicated with the command completion waiter implemented in the ec_poll() because: If IBF=1 blocked the first command byte write invoked in the task context ec_poll(), it would be kicked off upon IBF=0 interrupt or timed out and retried again in the task context. Remove this seperate and duplicate IBF=0 waiter. By doing so we can reduce the overall number of times to access the EC_SC(R) status register. Link: https://bugzilla.kernel.org/show_bug.cgi?id=70891 Link: https://bugzilla.kernel.org/show_bug.cgi?id=63931 Link: https://bugzilla.kernel.org/show_bug.cgi?id=59911 Reported-and-tested-by: Gareth Williams Reported-and-tested-by: Hans de Goede Reported-by: Barton Xu Tested-by: Steffen Weber Tested-by: Arthur Chen Signed-off-by: Lv Zheng Signed-off-by: Rafael J. Wysocki Signed-off-by: Jiri Slaby --- drivers/acpi/ec.c | 27 +-------------------------- 1 file changed, 1 insertion(+), 26 deletions(-) diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 6e091a96d023..7b52a724a0dd 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -288,23 +288,6 @@ static int acpi_ec_transaction_unlocked(struct acpi_ec *ec, return ret; } -static int ec_check_ibf0(struct acpi_ec *ec) -{ - u8 status = acpi_ec_read_status(ec); - return (status & ACPI_EC_FLAG_IBF) == 0; -} - -static int ec_wait_ibf0(struct acpi_ec *ec) -{ - unsigned long delay = jiffies + msecs_to_jiffies(ec_delay); - /* interrupt wait manually if GPE mode is not active */ - while (time_before(jiffies, delay)) - if (wait_event_timeout(ec->wait, ec_check_ibf0(ec), - msecs_to_jiffies(1))) - return 0; - return -ETIME; -} - static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t) { int status; @@ -325,12 +308,6 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t) goto unlock; } } - if (ec_wait_ibf0(ec)) { - pr_err(PREFIX "input buffer is not empty, " - "aborting transaction\n"); - status = -ETIME; - goto end; - } pr_debug(PREFIX "transaction start (cmd=0x%02x, addr=0x%02x)\n", t->command, t->wdata ? t->wdata[0] : 0); /* disable GPE during transaction if storm is detected */ @@ -354,7 +331,6 @@ static int acpi_ec_transaction(struct acpi_ec *ec, struct transaction *t) set_bit(EC_FLAGS_GPE_STORM, &ec->flags); } pr_debug(PREFIX "transaction end\n"); -end: if (ec->global_lock) acpi_release_global_lock(glk); unlock: @@ -680,8 +656,7 @@ static u32 acpi_ec_gpe_handler(acpi_handle gpe_device, spin_lock_irqsave(&ec->lock, flags); advance_transaction(ec); spin_unlock_irqrestore(&ec->lock, flags); - if (ec_transaction_completed(ec) && - (acpi_ec_read_status(ec) & ACPI_EC_FLAG_IBF) == 0) { + if (ec_transaction_completed(ec)) { wake_up(&ec->wait); ec_check_sci(ec, acpi_ec_read_status(ec)); } -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/