From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [merged] rtc-rtc-at91rm9200-fix-infinite-wait-for-ackupd-irq.patch removed from -mm tree Date: Mon, 09 Jun 2014 12:30:37 -0700 Message-ID: <53960b5d.QeJ8MvHo5/WR0MID%akpm@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53837 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753889AbaFITai (ORCPT ); Mon, 9 Jun 2014 15:30:38 -0400 Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: mm-commits@vger.kernel.org, stable@vger.kernel.org, plagnioj@jcrosoft.com, nicolas.ferre@atmel.com, linux@maxim.org.za, bevenson@melinkcorp.com, a.zummo@towertech.it, boris.brezillon@free-electrons.com Subject: [merged] rtc-rtc-at91rm9200-fix-infinite-wait-for-ackupd-irq.patch removed from -mm tree To: boris.brezillon@free-electrons.com,a.zummo@towertech.it,bevenson@melinkcorp.com,linux@maxim.org.za,nicolas.ferre@atmel.com,plagnioj@jcrosoft.com,stable@vger.kernel.org,mm-commits@vger.kernel.org From: akpm@linux-foundation.org Date: Mon, 09 Jun 2014 12:30:37 -0700 The patch titled Subject: rtc: rtc-at91rm9200: fix infinite wait for ACKUPD irq has been removed from the -mm tree. Its filename was rtc-rtc-at91rm9200-fix-infinite-wait-for-ackupd-irq.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Boris BREZILLON Subject: rtc: rtc-at91rm9200: fix infinite wait for ACKUPD irq The rtc user must wait at least 1 sec between each time/calandar update (see atmel's datasheet chapter "Updating Time/Calendar"). Use the 1Hz interrupt to update the at91_rtc_upd_rdy flag and wait for the at91_rtc_wait_upd_rdy event if the rtc is not ready. This patch fixes a deadlock in an uninterruptible wait when the RTC is updated more than once every second. AFAICT the bug is here from the beginning, but I think we should at least backport this fix to 3.10 and the following longterm and stable releases. Signed-off-by: Boris BREZILLON Reported-by: Bryan Evenson Tested-by: Bryan Evenson Cc: Andrew Victor Cc: Nicolas Ferre Cc: Jean-Christophe Plagniol-Villard Cc: Alessandro Zummo Cc: Signed-off-by: Andrew Morton --- drivers/rtc/rtc-at91rm9200.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff -puN drivers/rtc/rtc-at91rm9200.c~rtc-rtc-at91rm9200-fix-infinite-wait-for-ackupd-irq drivers/rtc/rtc-at91rm9200.c --- a/drivers/rtc/rtc-at91rm9200.c~rtc-rtc-at91rm9200-fix-infinite-wait-for-ackupd-irq +++ a/drivers/rtc/rtc-at91rm9200.c @@ -48,6 +48,7 @@ struct at91_rtc_config { static const struct at91_rtc_config *at91_rtc_config; static DECLARE_COMPLETION(at91_rtc_updated); +static DECLARE_COMPLETION(at91_rtc_upd_rdy); static unsigned int at91_alarm_year = AT91_RTC_EPOCH; static void __iomem *at91_rtc_regs; static int irq; @@ -161,6 +162,8 @@ static int at91_rtc_settime(struct devic 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec); + wait_for_completion(&at91_rtc_upd_rdy); + /* Stop Time/Calendar from counting */ cr = at91_rtc_read(AT91_RTC_CR); at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); @@ -183,7 +186,9 @@ static int at91_rtc_settime(struct devic /* Restart Time/Calendar */ cr = at91_rtc_read(AT91_RTC_CR); + at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_SECEV); at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM)); + at91_rtc_write_ier(AT91_RTC_SECEV); return 0; } @@ -290,8 +295,10 @@ static irqreturn_t at91_rtc_interrupt(in if (rtsr) { /* this interrupt is shared! Is it ours? */ if (rtsr & AT91_RTC_ALARM) events |= (RTC_AF | RTC_IRQF); - if (rtsr & AT91_RTC_SECEV) - events |= (RTC_UF | RTC_IRQF); + if (rtsr & AT91_RTC_SECEV) { + complete(&at91_rtc_upd_rdy); + at91_rtc_write_idr(AT91_RTC_SECEV); + } if (rtsr & AT91_RTC_ACKUPD) complete(&at91_rtc_updated); @@ -413,6 +420,11 @@ static int __init at91_rtc_probe(struct return PTR_ERR(rtc); platform_set_drvdata(pdev, rtc); + /* enable SECEV interrupt in order to initialize at91_rtc_upd_rdy + * completion. + */ + at91_rtc_write_ier(AT91_RTC_SECEV); + dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n"); return 0; } _ Patches currently in -mm which might be from boris.brezillon@free-electrons.com are origin.patch linux-next.patch