From patchwork Wed Jul 25 22:28:58 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephen Boyd X-Patchwork-Id: 949393 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-gpio-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.b="d5waiVkt"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 41bVJZ4X0Tz9s1R for ; Thu, 26 Jul 2018 08:29:18 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731586AbeGYXmu (ORCPT ); Wed, 25 Jul 2018 19:42:50 -0400 Received: from mail-pg1-f194.google.com ([209.85.215.194]:40097 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731575AbeGYXmu (ORCPT ); Wed, 25 Jul 2018 19:42:50 -0400 Received: by mail-pg1-f194.google.com with SMTP id x5-v6so6201963pgp.7 for ; Wed, 25 Jul 2018 15:29:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Ink+Zn8JKKzqrmjhPVKUxo0wTebG1Ak/9NW4SCv+NEs=; b=d5waiVktb7Skwo+wZNY5Gu3m9T6CTmlCMM1asro2WMbqNmst/sXeI5axBsr3BRpBFM 7k4V4/j/7gIrAqRKTsFsnZaviZ/v2SY8CBSIOanvpeUNOka7HopjreorUONwHhx0BSRa V6nNctLVYwWXCi0h8ksFE1aF386LzWzz0fJro= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Ink+Zn8JKKzqrmjhPVKUxo0wTebG1Ak/9NW4SCv+NEs=; b=oiTl0hyN8ZFp5Q/+nTIddvI8F4uz4BqvgnxeNiP5pAtiVVks+XT8LsHJPjVZ2mjor9 J/wOK2DBa+okLeTftcbScxiixYmjvYD5SeBh6mdbgU+kbrXb01y3buIw39fBXHs7Niv4 2ga544m5gFIYOlLxih4iprEJUg1TCu62XkD2KgWBfuCJzSdhQywHVTDUolTSFl2752KW IfTpI1hbvLeGiVxDWMYhB4mEDtrY6TKpriWrw73LpDV6LTrrWd45gezcL1NRKP26TDi5 G4FaUUmEy6HD51F4/VcUjdOhwiahk3eHYtbuxoatzH/cZPPOc9aNgmH+gbCkpmL+OpwB 255A== X-Gm-Message-State: AOUpUlFgGLJjWfg2AAIU3seYpzWmsjDjYhy1z7+DpvSCkc/CpMOukrHx IRofVYl8hHO1tWFQpJ+Zy6NhJw== X-Google-Smtp-Source: AAOMgpfrezkXI2QKska/+IpXiR8SnBknmM6lpJPDhofAwAKPOJUysXllMOIDO48GEoEOj33pIPZogw== X-Received: by 2002:a62:669b:: with SMTP id s27-v6mr21979355pfj.224.1532557744045; Wed, 25 Jul 2018 15:29:04 -0700 (PDT) Received: from swboyd.mtv.corp.google.com ([2620:0:1000:1511:d30e:62c6:f82c:ff40]) by smtp.gmail.com with ESMTPSA id o21-v6sm23839234pfa.54.2018.07.25.15.29.03 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 25 Jul 2018 15:29:03 -0700 (PDT) From: Stephen Boyd To: Linus Walleij Cc: linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, linux-arm-msm@vger.kernel.org, Bjorn Andersson , Doug Anderson Subject: [PATCH v2 1/3] pinctrl: msm: Really mask level interrupts to prevent latching Date: Wed, 25 Jul 2018 15:28:58 -0700 Message-Id: <20180725222900.33231-2-swboyd@chromium.org> X-Mailer: git-send-email 2.18.0.233.g985f88cf7e-goog In-Reply-To: <20180725222900.33231-1-swboyd@chromium.org> References: <20180725222900.33231-1-swboyd@chromium.org> Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org The interrupt controller hardware in this pin controller has two status enable bits. The first "normal" status enable bit enables or disables the summary interrupt line being raised when a gpio interrupt triggers and the "raw" status enable bit allows or prevents the hardware from latching an interrupt into the status register for a gpio interrupt. Currently we just toggle the "normal" status enable bit in the mask and unmask ops so that the summary irq interrupt going to the CPU's interrupt controller doesn't trigger for the masked gpio interrupt. For a level triggered interrupt, the flow would be as follows: the pin controller sees the interrupt, latches the status into the status register, raises the summary irq to the CPU, summary irq handler runs and calls handle_level_irq(), handle_level_irq() masks and acks the gpio interrupt, the interrupt handler runs, and finally unmask the interrupt. When the interrupt handler completes, we expect that the interrupt line level will go back to the deasserted state so the genirq code can unmask the interrupt without it triggering again. If we only mask the interrupt by clearing the "normal" status enable bit then we'll ack the interrupt but it will continue to show up as pending in the status register because the raw status bit is enabled, the hardware hasn't deasserted the line, and thus the asserted state latches into the status register again. When the hardware deasserts the interrupt the pin controller still thinks there is a pending unserviced level interrupt because it latched it earlier. This behavior causes software to see an extra interrupt for level type interrupts each time the interrupt is handled. Let's fix this by clearing the raw status enable bit for level type interrupts so that the hardware stops latching the status of the interrupt after we ack it. We don't do this for edge type interrupts because it seems that toggling the raw status enable bit for edge type interrupts causes spurious edge interrupts. Cc: Bjorn Andersson Cc: Doug Anderson Signed-off-by: Stephen Boyd --- Changes from v1: - Squashed raw_status_bit write into same write on unmask (Doug Andersson) drivers/pinctrl/qcom/pinctrl-msm.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c index 2155a30c282b..3970dc599092 100644 --- a/drivers/pinctrl/qcom/pinctrl-msm.c +++ b/drivers/pinctrl/qcom/pinctrl-msm.c @@ -634,6 +634,19 @@ static void msm_gpio_irq_mask(struct irq_data *d) raw_spin_lock_irqsave(&pctrl->lock, flags); val = readl(pctrl->regs + g->intr_cfg_reg); + /* + * Leaving the RAW_STATUS_EN bit enabled causes level interrupts that + * are still asserted to re-latch after we ack them. Clear the raw + * status enable bit too so the interrupt can't even latch into the + * hardware while it's masked, but only do this for level interrupts + * because edge interrupts have a problem with the raw status bit + * toggling and causing spurious interrupts. + */ + if (irqd_get_trigger_type(d) & IRQ_TYPE_LEVEL_MASK) { + val &= ~BIT(g->intr_raw_status_bit); + writel(val, pctrl->regs + g->intr_cfg_reg); + } + val &= ~BIT(g->intr_enable_bit); writel(val, pctrl->regs + g->intr_cfg_reg); @@ -655,6 +668,7 @@ static void msm_gpio_irq_unmask(struct irq_data *d) raw_spin_lock_irqsave(&pctrl->lock, flags); val = readl(pctrl->regs + g->intr_cfg_reg); + val |= BIT(g->intr_raw_status_bit); val |= BIT(g->intr_enable_bit); writel(val, pctrl->regs + g->intr_cfg_reg);