From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57754 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750928AbcKOTJz (ORCPT ); Tue, 15 Nov 2016 14:09:55 -0500 Subject: Patch "ARC: timer: rtc: implement read loop in "C" vs. inline asm" has been added to the 4.8-stable tree To: vgupta@synopsys.com, daniel.lezcano@linaro.org, gregkh@linuxfoundation.org Cc: , From: Date: Tue, 15 Nov 2016 20:09:47 +0100 Message-ID: <147923698712210@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled ARC: timer: rtc: implement read loop in "C" vs. inline asm to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: arc-timer-rtc-implement-read-loop-in-c-vs.-inline-asm.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 922cc171998ac3dbe74d57011ef7ed57e9b0d7df Mon Sep 17 00:00:00 2001 From: Vineet Gupta Date: Mon, 31 Oct 2016 14:09:52 -0700 Subject: ARC: timer: rtc: implement read loop in "C" vs. inline asm From: Vineet Gupta commit 922cc171998ac3dbe74d57011ef7ed57e9b0d7df upstream. The current code doesn't even compile as somehow the inline assembly can't see the register names defined as ARC_RTC_* I'm pretty sure It worked when I first got it merged, but the tools were definitely different then. So better to write this in "C" anyways. Acked-by: Daniel Lezcano Signed-off-by: Vineet Gupta Signed-off-by: Greg Kroah-Hartman --- arch/arc/kernel/time.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) --- a/arch/arc/kernel/time.c +++ b/arch/arc/kernel/time.c @@ -152,14 +152,17 @@ static cycle_t arc_read_rtc(struct clock cycle_t full; } stamp; - - __asm__ __volatile( - "1: \n" - " lr %0, [AUX_RTC_LOW] \n" - " lr %1, [AUX_RTC_HIGH] \n" - " lr %2, [AUX_RTC_CTRL] \n" - " bbit0.nt %2, 31, 1b \n" - : "=r" (stamp.low), "=r" (stamp.high), "=r" (status)); + /* + * hardware has an internal state machine which tracks readout of + * low/high and updates the CTRL.status if + * - interrupt/exception taken between the two reads + * - high increments after low has been read + */ + do { + stamp.low = read_aux_reg(AUX_RTC_LOW); + stamp.high = read_aux_reg(AUX_RTC_HIGH); + status = read_aux_reg(AUX_RTC_CTRL); + } while (!(status & _BITUL(31))); return stamp.full; } Patches currently in stable-queue which might be from vgupta@synopsys.com are queue-4.8/arc-implement-arch-specific-dma_map_ops.mmap.patch queue-4.8/arc-timer-rtc-implement-read-loop-in-c-vs.-inline-asm.patch