From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B18BC388F9 for ; Wed, 11 Nov 2020 17:06:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB67D2074B for ; Wed, 11 Nov 2020 17:06:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727329AbgKKRGY (ORCPT ); Wed, 11 Nov 2020 12:06:24 -0500 Received: from muru.com ([72.249.23.125]:48078 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725995AbgKKRGX (ORCPT ); Wed, 11 Nov 2020 12:06:23 -0500 Received: from hillo.muru.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTP id 7DAF88126; Wed, 11 Nov 2020 17:06:27 +0000 (UTC) From: Tony Lindgren To: Lee Jones Cc: linux-kernel@vger.kernel.org, Carl Philipp Klemm , Laxminath Kasam , Merlijn Wajer , Mark Brown , Pavel Machek , Sebastian Reichel , Tim Harvey Subject: [PATCH] mfd: cpcap: Fix interrupt regression with regmap clear_ack Date: Wed, 11 Nov 2020 19:06:13 +0200 Message-Id: <20201111170613.46057-1-tony@atomide.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With commit 3a6f0fb7b8eb ("regmap: irq: Add support to clear ack registers"), the cpcap interrupts are no longer getting acked properly leading to a very unresponsive device with CPUs fully loaded spinning in the threaded IRQ handlers. To me it looks like the clear_ack commit above actually fixed a long standing bug in regmap_irq_thread() where we unconditionally acked the interrupts earlier without considering ack_invert. And the issue with cpcap started happening as we now also consider ack_invert. Tim Harvey tried to fix this issue earlier with "[PATCH v2] regmap: irq: fix ack-invert", but the reading of the ack register was considered unnecessary for just ack_invert, and we did not have clear_ack available yet. As the cpcap irqs worked both with and without ack_invert earlier because of the unconditional ack, the problem remained hidden until now. Also, looks like the earlier v3.0.8 based Motorola Android Linux kernel does clear_ack style read-clear-write with "ireg_val & ~mreg_val" instead of just ack_invert style write. So let's switch cpcap to use clear_ack to fix the issue. Fixes: 3a6f0fb7b8eb ("regmap: irq: Add support to clear ack registers") Cc: Carl Philipp Klemm Cc: Laxminath Kasam Cc: Merlijn Wajer Cc: Mark Brown Cc: Pavel Machek Cc: Sebastian Reichel Cc: Tim Harvey Signed-off-by: Tony Lindgren --- drivers/mfd/motorola-cpcap.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/mfd/motorola-cpcap.c b/drivers/mfd/motorola-cpcap.c --- a/drivers/mfd/motorola-cpcap.c +++ b/drivers/mfd/motorola-cpcap.c @@ -97,7 +97,7 @@ static struct regmap_irq_chip cpcap_irq_chip[CPCAP_NR_IRQ_CHIPS] = { .ack_base = CPCAP_REG_MI1, .mask_base = CPCAP_REG_MIM1, .use_ack = true, - .ack_invert = true, + .clear_ack = true, }, { .name = "cpcap-m2", @@ -106,7 +106,7 @@ static struct regmap_irq_chip cpcap_irq_chip[CPCAP_NR_IRQ_CHIPS] = { .ack_base = CPCAP_REG_MI2, .mask_base = CPCAP_REG_MIM2, .use_ack = true, - .ack_invert = true, + .clear_ack = true, }, { .name = "cpcap1-4", @@ -115,7 +115,7 @@ static struct regmap_irq_chip cpcap_irq_chip[CPCAP_NR_IRQ_CHIPS] = { .ack_base = CPCAP_REG_INT1, .mask_base = CPCAP_REG_INTM1, .use_ack = true, - .ack_invert = true, + .clear_ack = true, }, }; -- 2.29.2