From patchwork Mon Aug 26 15:25:29 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudiu Beznea X-Patchwork-Id: 822578 Received: from mail-lj1-f182.google.com (mail-lj1-f182.google.com [209.85.208.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3C0B21946C7 for ; Mon, 26 Aug 2024 15:25:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.208.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724685949; cv=none; b=SPM0Au/qPwB2sBfa6BSju1yHmGTzFs1xq9vvtEIxcuAvnauijRIYs+VyLugCd7TfYem0kscuRKTqHYYB504WmYpcO8jKjqLVnNObF0mSjX7b8swU1d9v471KvYGRvrTgmr/1iBlNlAJzR8ZK5ixz7YaUTfRF5iBApwxuwGKmft0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724685949; c=relaxed/simple; bh=XWVC5HUqa4FOSOr6jFDlVoBbwf0lh/Ow1BEEkfWRRYA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=uy2bcMn3zXC2i4aJixdn5AiBoqNaRMqD/UF4Re6kgSJEElDtKy8RW5dlCiCP5a6m/92D44AEHlzZ6NF9gsKoDO3YcvwaWI3jg9GXdhRrEHmDmrl5kGcaQJ1E2/UkAE0NVu4s+DzVtrk91qGRtdZJp01PLSegDE/LUnwLrClpGbo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tuxon.dev; spf=pass smtp.mailfrom=tuxon.dev; dkim=pass (2048-bit key) header.d=tuxon.dev header.i=@tuxon.dev header.b=gbldyVGl; arc=none smtp.client-ip=209.85.208.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=tuxon.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=tuxon.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=tuxon.dev header.i=@tuxon.dev header.b="gbldyVGl" Received: by mail-lj1-f182.google.com with SMTP id 38308e7fff4ca-2f3e071eb64so62797041fa.1 for ; Mon, 26 Aug 2024 08:25:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tuxon.dev; s=google; t=1724685944; x=1725290744; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=4X7RWHf9c2Nsin/P0/MRWONZQiMlvlo7ShNISxGRapI=; b=gbldyVGlJeZfkyhrR68yz9aFdsGuOpqlIaqQo/94wYzFHVjo+tJVVbB5oHkrcafTUU GM7WQ3KRyNuMoA0IVDEBe2D6dq2vI7XQkIWJNokLZqLSlVSiLnUYtj+ZMdFdAGSs5j72 zfQUN+EECMn8Q8xAtIiR3dRZ04xkeon+VW5Fkcu3HfDsYh4B1jgvdd2EUHnwExvyUxra zQj2BabNosdbC1tmhTa5n70iy1q3i3XagGiiUU7brPRcSwOpZg5eCvDHgEA4/VpQmCrp 7yJEvqSkXD6EZY2DRaginvaTlZatcaRoijxuVMbmeGvMz9Vnw4oaOEJmEBfkicSb8aFl 0zeQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724685944; x=1725290744; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=4X7RWHf9c2Nsin/P0/MRWONZQiMlvlo7ShNISxGRapI=; b=bRJm87Sxmhyu0+bL8k4wj8EGgKVo2pmwZeJnhyef5EiUr9ZroZbhwRoIMBYjrZHlEy 23LVgiHcwAs5jGgw1l+oNM4Jq9ZpHIgcdbt/EeD2zZpSi+MkZIx/oc9/tpxa9bnaYvIT 1k4E/PxPeM+wTl7N/hg+WdlHgcWT7DBF+rQA4qyc1+866KChxE2oIYrbQFd+79QvfFFX 8A4AftZw0x081uLtQ1LnC7GcSwMJhf3NQlTVfOnMp4ab4GJXH32LA3UT9XLzzQ10rKUF 8y9B+huyICl8AJ9zF/59UP1qNyu4NVfQYBYMtx+0peTqD6E5WgAHud+gz6KnVrDbaMV8 6fWA== X-Forwarded-Encrypted: i=1; AJvYcCURM+b2A4j7QU2dNjzOGOFrF+tkf2bXdeUO8kBMFrEw8aRb+iIH5NlvkEjmVsfkfCGlgL8odHHQCA==@vger.kernel.org X-Gm-Message-State: AOJu0YwzdIc6Wzfbc2ficZIxtb6OtfDit4gxHyA2a+diSQhVD/BmDQCc QyOP7iidXx5BxaS0EAMHLBWejnigzk73qLrm0ehVoJPJaIikcfsP5q11TRo+AsE= X-Google-Smtp-Source: AGHT+IG/0Rw3KjFlXHyoNSA5O3duIeqvGmjekfYBFzagXObV7ksdyWtivPN8UapEZYUG+dChI+97qw== X-Received: by 2002:a2e:b704:0:b0:2ef:2905:f36d with SMTP id 38308e7fff4ca-2f4f5750715mr71543281fa.16.1724685944207; Mon, 26 Aug 2024 08:25:44 -0700 (PDT) Received: from claudiu-X670E-Pro-RS.. ([82.78.167.144]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a868f437d5fsm683005866b.99.2024.08.26.08.25.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Aug 2024 08:25:43 -0700 (PDT) From: Claudiu X-Google-Original-From: Claudiu To: geert+renesas@glider.be, mturquette@baylibre.com, sboyd@kernel.org, wim@linux-watchdog.org, linux@roeck-us.net, ulf.hansson@linaro.org Cc: linux-renesas-soc@vger.kernel.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-pm@vger.kernel.org, claudiu.beznea@tuxon.dev, Claudiu Beznea Subject: [PATCH 3/3] watchdog: rzg2l_wdt: Power on the watchdog domain in the restart handler Date: Mon, 26 Aug 2024 18:25:29 +0300 Message-Id: <20240826152529.2080248-4-claudiu.beznea.uj@bp.renesas.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240826152529.2080248-1-claudiu.beznea.uj@bp.renesas.com> References: <20240826152529.2080248-1-claudiu.beznea.uj@bp.renesas.com> Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Claudiu Beznea On RZ/G3S the watchdog can be part of a software-controlled PM domain. In this case, the watchdog device need to be powered on in struct watchdog_ops::restart API. This can be done though pm_runtime_resume_and_get() API if the watchdog PM domain and watchdog device are marked as IRQ safe. We mark the watchdog PM domain as IRQ safe with GENPD_FLAG_IRQ_SAFE when the watchdog PM domain is registered and the watchdog device though pm_runtime_irq_safe(). Before commit e4cf89596c1f ("watchdog: rzg2l_wdt: Fix 'BUG: Invalid wait context'") pm_runtime_get_sync() was used in watchdog restart handler (which is similar to pm_runtime_resume_and_get() except the later one handles the runtime resume errors). Commit e4cf89596c1f ("watchdog: rzg2l_wdt: Fix 'BUG: Invalid wait context'") dropped the pm_runtime_get_sync() and replaced it with clk_prepare_enable() to avoid invalid wait context due to genpd_lock() in genpd_runtime_resume() being called from atomic context. But clk_prepare_enable() doesn't fit for this either (as reported by Ulf Hansson) as clk_prepare() can also sleep (it just not throw invalid wait context warning as it is not written for this). Because the watchdog device is marked now as IRQ safe (though this patch) the irq_safe_dev_in_sleep_domain() call from genpd_runtime_resume() returns 1 for devices not registering an IRQ safe PM domain for watchdog (as the watchdog device is IRQ safe, PM domain is not and watchdog PM domain is always-on), this being the case of RZ/G2 devices that uses this driver, we can now drop also the clk_prepare_enable() calls in restart handler and rely on pm_runtime_resume_and_get(). Thus, drop clk_prepare_enable() and use pm_runtime_resume_and_get() in watchdog restart handler. Signed-off-by: Claudiu Beznea Acked-by: Guenter Roeck --- drivers/watchdog/rzg2l_wdt.c | 21 +++++++++++++++++++-- 1 file changed, 19 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c index 2a35f890a288..e9e0408c96f7 100644 --- a/drivers/watchdog/rzg2l_wdt.c +++ b/drivers/watchdog/rzg2l_wdt.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -166,8 +167,23 @@ static int rzg2l_wdt_restart(struct watchdog_device *wdev, struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev); int ret; - clk_prepare_enable(priv->pclk); - clk_prepare_enable(priv->osc_clk); + /* + * In case of RZ/G3S the watchdog device may be part of an IRQ safe power + * domain that is currently powered off. In this case we need to power + * it on before accessing registers. Along with this the clocks will be + * enabled. We don't undo the pm_runtime_resume_and_get() as the device + * need to be on for the reboot to happen. + * + * For the rest of RZ/G2 devices (and for RZ/G3S with old device trees + * where PM domains are registered like on RZ/G2 devices) it is safe + * to call pm_runtime_resume_and_get() as the + * irq_safe_dev_in_sleep_domain() call in genpd_runtime_resume() + * returns non zero value and the genpd_lock() is avoided, thus, there + * will be no invalid wait context reported by lockdep. + */ + ret = pm_runtime_resume_and_get(wdev->parent); + if (ret) + return ret; if (priv->devtype == WDT_RZG2L) { ret = reset_control_deassert(priv->rstc); @@ -275,6 +291,7 @@ static int rzg2l_wdt_probe(struct platform_device *pdev) priv->devtype = (uintptr_t)of_device_get_match_data(dev); + pm_runtime_irq_safe(&pdev->dev); pm_runtime_enable(&pdev->dev); priv->wdev.info = &rzg2l_wdt_ident;