From patchwork Wed Feb 26 15:42:40 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kieran Clancy X-Patchwork-Id: 3725131 Return-Path: X-Original-To: patchwork-linux-acpi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 21C02BF13A for ; Wed, 26 Feb 2014 15:44:00 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 14984201D3 for ; Wed, 26 Feb 2014 15:43:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 624C1201BA for ; Wed, 26 Feb 2014 15:43:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753036AbaBZPnp (ORCPT ); Wed, 26 Feb 2014 10:43:45 -0500 Received: from mail-pa0-f54.google.com ([209.85.220.54]:36571 "EHLO mail-pa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753013AbaBZPno (ORCPT ); Wed, 26 Feb 2014 10:43:44 -0500 Received: by mail-pa0-f54.google.com with SMTP id fa1so1140494pad.27 for ; Wed, 26 Feb 2014 07:43:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=ZY89wQmNL3yTEBWxCfyvaojZpHXC4VNntNHpruA5+vM=; b=HGObC78hMV9gQQCGpTEdWmq7LUMMQMv1He+/BVEvWTJOlIbfXyYf4ECLejDPXgmmrE vuN5W0LIxoCAhctr2SXU9gYxWv62nFJ7iG8tohNv48+1rscFY/qBFJRfPnpr74F51Bs1 pAkkFIV+eU3KxUqRKWdLMGQQyPzwXVL/AgrbWo2OCRiLKCuJrlGApteLIwLDeLvIUebC +y5P9VkopmhT1jgSZT1FnKmfSCIC0S5GRx8qpMdPqmtXXyujrGPji547uGXijplvHh4S n+vy2JTG0k1xxxdPmYwmx9gRaWdgGBC3hDLsK+/7Fqc4Q+oIomLv8/Gs3Cv3ATvPukYb zlgw== X-Received: by 10.66.250.202 with SMTP id ze10mr9462074pac.153.1393429423611; Wed, 26 Feb 2014 07:43:43 -0800 (PST) Received: from kbook.kieranclancy.com. (kieranclancy.com. [60.240.75.5]) by mx.google.com with ESMTPSA id vf7sm4514467pbc.5.2014.02.26.07.43.37 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 26 Feb 2014 07:43:42 -0800 (PST) From: Kieran Clancy To: Len Brown , "Rafael J. Wysocki" Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Kieran Clancy , Lan Tianyu , Juan Manuel Cabo , Dennis Jansen Subject: [PATCH] ACPI / EC: Clear stale EC events on Samsung systems Date: Thu, 27 Feb 2014 02:12:40 +1030 Message-Id: <1393429360-4344-1-git-send-email-clancy.kieran@gmail.com> X-Mailer: git-send-email 1.8.5.3 Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A number of Samsung notebooks (530Uxx/535Uxx/540Uxx/550Pxx/900Xxx/etc) continue to log events during sleep (lid open/close, AC plug/unplug, battery level change), which accumulate in the EC until a buffer fills. After the buffer is full (tests suggest it holds 8 events), GPEs stop being triggered for new events. This state persists on wake or even on power cycle, and prevents new events from being registered until the EC is manually polled. This is the root cause of a number of bugs, including AC not being detected properly, lid close not triggering suspend, and low ambient light not triggering the keyboard backlight. The bug also seemed to be responsible for performance issues on at least one user's machine. Juan Manuel Cabo found the cause of bug and the workaround of polling the EC manually on wake. This patch: - Adds a function acpi_ec_clear() which polls the EC, at most ACPI_EC_CLEAR_MAX (currently 20) times. A warning is logged if this limit is reached. - Adds a flag EC_FLAGS_CLEAR_ON_RESUME which is set to 1 if the DMI system vendor is Samsung. This check could be replaced by several more specific DMI vendor/product pairs, but it's likely that the bug affects more Samsung products than just the five series mentioned above. Further, it should not be harmful to run acpi_ec_clear() on systems without the bug; it will return immediately after finding no data waiting. - Runs acpi_ec_clear() on initialisation (boot), from acpi_ec_add() - Runs acpi_ec_clear() on wake, from acpi_ec_unblock_transactions() References: https://bugzilla.kernel.org/show_bug.cgi?id=44161 References: https://bugzilla.kernel.org/show_bug.cgi?id=45461 References: https://bugzilla.kernel.org/show_bug.cgi?id=57271 Signed-off-by: Kieran Clancy Signed-off-by: Lan Tianyu Signed-off-by: Juan Manuel Cabo Signed-off-by: Dennis Jansen Tested-by: Maurizio D'Addona Tested-by: San Zamoyski Signed-off-by: Kieran Clancy Signed-off-by: Lan Tianyu Reviewed-by: Lan Tianyu Reviewed-by: Dennis Jansen --- drivers/acpi/ec.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c index 959d41a..f437d9a 100644 --- a/drivers/acpi/ec.c +++ b/drivers/acpi/ec.c @@ -67,6 +67,8 @@ enum ec_command { #define ACPI_EC_DELAY 500 /* Wait 500ms max. during EC ops */ #define ACPI_EC_UDELAY_GLK 1000 /* Wait 1ms max. to get global lock */ #define ACPI_EC_MSI_UDELAY 550 /* Wait 550us for MSI EC */ +#define ACPI_EC_CLEAR_MAX 20 /* Maximum number of events to query + * when trying to clear the EC */ enum { EC_FLAGS_QUERY_PENDING, /* Query is pending */ @@ -116,6 +118,7 @@ EXPORT_SYMBOL(first_ec); static int EC_FLAGS_MSI; /* Out-of-spec MSI controller */ static int EC_FLAGS_VALIDATE_ECDT; /* ASUStec ECDTs need to be validated */ static int EC_FLAGS_SKIP_DSDT_SCAN; /* Not all BIOS survive early DSDT scan */ +static int EC_FLAGS_CLEAR_ON_RESUME; /* EC should be polled on boot/resume */ /* -------------------------------------------------------------------------- Transaction Management @@ -440,6 +443,26 @@ acpi_handle ec_get_handle(void) EXPORT_SYMBOL(ec_get_handle); +static int acpi_ec_query_unlocked(struct acpi_ec *ec, u8 *data); + +/* run with locked ec mutex */ +static void acpi_ec_clear(struct acpi_ec *ec) +{ + int i, status; + u8 value = 0; + + for (i = 0; i < ACPI_EC_CLEAR_MAX; i++) { + status = acpi_ec_query_unlocked(ec, &value); + if (status || !value) + break; + } + + if (i == ACPI_EC_CLEAR_MAX) + pr_warn("Warning: Maximum of %d stale EC events cleared\n", i); + else + pr_info("%d stale EC events cleared\n", i); +} + void acpi_ec_block_transactions(void) { struct acpi_ec *ec = first_ec; @@ -463,6 +486,10 @@ void acpi_ec_unblock_transactions(void) mutex_lock(&ec->mutex); /* Allow transactions to be carried out again */ clear_bit(EC_FLAGS_BLOCKED, &ec->flags); + + if (EC_FLAGS_CLEAR_ON_RESUME) + acpi_ec_clear(ec); + mutex_unlock(&ec->mutex); } @@ -821,6 +848,13 @@ static int acpi_ec_add(struct acpi_device *device) /* EC is fully operational, allow queries */ clear_bit(EC_FLAGS_QUERY_PENDING, &ec->flags); + + /* Some hardware may need the EC to be cleared before use */ + if (EC_FLAGS_CLEAR_ON_RESUME) { + mutex_lock(&ec->mutex); + acpi_ec_clear(ec); + mutex_unlock(&ec->mutex); + } return ret; } @@ -922,6 +956,30 @@ static int ec_enlarge_storm_threshold(const struct dmi_system_id *id) return 0; } +/* + * On some hardware it is necessary to clear events accumulated by the EC during + * sleep. These ECs stop reporting GPEs until they are manually polled, if too + * many events are accumulated. (e.g. Samsung Series 5/9 notebooks) + * + * https://bugzilla.kernel.org/show_bug.cgi?id=44161 + * + * Ideally, the EC should also be instructed not to accumulate events during + * sleep (which Windows seems to do somehow), but the interface to control this + * behaviour is not known at this time. + * + * Models known to be affected are Samsung 530Uxx/535Uxx/540Uxx/550Pxx/900Xxx, + * however it is very likely that other Samsung models are affected. + * + * On systems which don't accumulate EC events during sleep, this extra check + * should be harmless. + */ +static int ec_clear_on_resume(const struct dmi_system_id *id) +{ + pr_debug("Detected system needing EC poll on resume.\n"); + EC_FLAGS_CLEAR_ON_RESUME = 1; + return 0; +} + static struct dmi_system_id ec_dmi_table[] __initdata = { { ec_skip_dsdt_scan, "Compal JFL92", { @@ -965,6 +1023,9 @@ static struct dmi_system_id ec_dmi_table[] __initdata = { ec_validate_ecdt, "ASUS hardware", { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTek Computer Inc."), DMI_MATCH(DMI_PRODUCT_NAME, "L4R"),}, NULL}, + { + ec_clear_on_resume, "Samsung hardware", { + DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD.")}, NULL}, {}, };