Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754557AbaB0CdP (ORCPT ); Wed, 26 Feb 2014 21:33:15 -0500 Received: from mail-yh0-f52.google.com ([209.85.213.52]:56232 "EHLO mail-yh0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753685AbaB0CdN (ORCPT ); Wed, 26 Feb 2014 21:33:13 -0500 Message-ID: <530EA3E5.3010102@gmail.com> Date: Wed, 26 Feb 2014 23:33:09 -0300 From: Juan Manuel Cabo User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: Li Guang , Kieran Clancy CC: Len Brown , "Rafael J. Wysocki" , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, Lan Tianyu , Dennis Jansen Subject: Re: [PATCH] ACPI / EC: Clear stale EC events on Samsung systems References: <1393429360-4344-1-git-send-email-clancy.kieran@gmail.com> <530E9BEF.8080601@cn.fujitsu.com> In-Reply-To: <530E9BEF.8080601@cn.fujitsu.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > that's really nasty EC firmware! Yes! And this bug has been unsolved for about two years. > 20 is enough? > the query index is length of a byte. > According to our humble tests, 8 is the maximum number of accumulated events. For instance, if the one plugs or unplugs the PSU 16 times, (or battery % changes 16 times) during S3 sleep, then the EC returns no more than 8 events when polled by this patch or by my userspace util. And having reached 8 events, it won't produce its GPE until queried. > the query index is length of a byte. There is no query index, unless you refer to something else (I'm sorry if its something that escapes me). For us, a query is just: send 0x84 through EC CMD port, and read status from CMD port and event type from EC DATA port. This is done with the usual ec.c functions that would handle a query after a GPE interrupt, but using them instead to poll (not GPE initiated) at awake. The EC would then return status without 0x20 mask and 'event type'==0 when no more left. -- Juan Manuel Cabo >> >> 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 */ >> > > seems name is implicit, what about EC_FLAGS_QEVENT_CLR_ON_RESUME? > seems too long :-) > >> >> /* -------------------------------------------------------------------------- >> 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 */ >> > > description is implicit, should specify what we clear is Q event, not EC. > > Thanks! > Li Guang > >> + 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}, >> {}, >> }; >> >> > > -- 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/