From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753095AbbBWQ01 (ORCPT ); Mon, 23 Feb 2015 11:26:27 -0500 Received: from mailout2.samsung.com ([203.254.224.25]:36652 "EHLO mailout2.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752545AbbBWQ0X (ORCPT ); Mon, 23 Feb 2015 11:26:23 -0500 X-AuditID: cbfee61b-f79d76d0000024d6-e8-54eb54ac5577 From: Bartlomiej Zolnierkiewicz To: linux-arm-kernel@lists.infradead.org Cc: Krzysztof Kozlowski , Kukjin Kim , linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, Kyungmin Park , stable@vger.kernel.org, Marek Szyprowski Subject: Re: [RESEND PATCH] ARM: EXYNOS: Fix failed second suspend on Exynos4 Date: Mon, 23 Feb 2015 17:25:48 +0100 Message-id: <2802418.zt8CxNGGkT@amdc1032> User-Agent: KMail/4.8.4 (Linux/3.2.0-70-generic-pae; KDE/4.8.5; i686; ; ) In-reply-to: <1424256325-16659-1-git-send-email-k.kozlowski@samsung.com> References: <1424256325-16659-1-git-send-email-k.kozlowski@samsung.com> MIME-version: 1.0 Content-transfer-encoding: 7Bit Content-type: text/plain; charset=us-ascii X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrFLMWRmVeSWpSXmKPExsVy+t9jQd01Ia9DDHb/MLF4/cLQov/xa2aL s01v2C02Pb7GanF51xw2ixnn9zFZrD1yl91iwcZHjA4cHptWdbJ5bF5S79G3ZRWjx+dNcgEs UVw2Kak5mWWpRfp2CVwZL/cvYi24xV0xZ90PpgbGw5xdjJwcEgImEq8u3meCsMUkLtxbz9bF yMUhJDCdUWL3z8csEE4Lk8Thr/tZQarYBKwkJravYgSxRQQ0JKZ0PWYHKWIWaGeS+DK7D6xI WMBX4smtZhYQm0VAVWLujFY2EJtXQFNi7vy3zCC2qICnxM7pB8AGcQp4SKz6dxqohgNom7vE uztpEOWCEj8m3wMbwywgL7Fv/1RWCFtLYv3O40wTGAVmISmbhaRsFpKyBYzMqxhFUwuSC4qT 0nON9IoTc4tL89L1kvNzNzGCQ/yZ9A7GVQ0WhxgFOBiVeHgbcl+FCLEmlhVX5h5ilOBgVhLh faP7OkSINyWxsiq1KD++qDQntfgQozQHi5I4r5J9W4iQQHpiSWp2ampBahFMlomDU6qBkXfv bm+HmGMhXM9yt1toHDj2Jp1XMcar93l9wXqZG9nnp8R8atAX7XGfoavZcZOt677l5JZdS7nq +yOZwox0D53OKvJ0WbpbMvDxxO3qQfd+xnkqhpbc+Bi4etbutlq9q2vn3d9anvHepbp87tZl C83Pt9ya8OfQxIaDpxOCGirbo8pZT0i2KrEUZyQaajEXFScCADnUWUttAgAA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On Wednesday, February 18, 2015 11:45:25 AM Krzysztof Kozlowski wrote: > On Exynos4412 boards (Trats2, Odroid U3) after enabling L2 cache in > 56b60b8bce4a ("ARM: 8265/1: dts: exynos4: Add nodes for L2 cache > controller") the second suspend to RAM failed. First suspend worked fine > but the next one hang just after powering down of secondary CPUs (system > consumed energy as it would be running but was not responsive). > > The issue was caused by enabling delayed reset assertion for CPU0 just > after issuing power down of cores. This was introduced for Exynos4 in > 13cfa6c4f7fa ("ARM: EXYNOS: Fix CPU idle clock down after CPU off"). > > The whole behavior is not well documented but after checking with vendor > code this should be done like this (on Exynos4): > 1. Enable delayed reset assertion when system is running (for all CPUs). > 2. Disable delayed reset assertion before suspending the system. > This can be done after powering off secondary CPUs. > 3. Re-enable the delayed reset assertion when system is resumed. > > Signed-off-by: Krzysztof Kozlowski > Fixes: 13cfa6c4f7fa ("ARM: EXYNOS: Fix CPU idle clock down after CPU off") > Cc: It turned out that this patch is also needed to fix cpuidle AFTR mode hang on Trats2. Tested-by: Bartlomiej Zolnierkiewicz Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics