From patchwork Wed Aug 28 14:06:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudiu Beznea X-Patchwork-Id: 823409 Received: from mail-ej1-f43.google.com (mail-ej1-f43.google.com [209.85.218.43]) (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 65FCC18953A for ; Wed, 28 Aug 2024 14:06:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.43 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724853982; cv=none; b=S3TEoFN3wyVqqm7beNuuL2nmjrN8IIbaXwKrAZv9F+yCYyYkuPPJTp9CX2XGCUprY3zLQirFpyEVe3Nk0Xqur472jvoA3cUIQyy8HzeQznmuffRaMRxiQqWhjle/mu5GSoXFjZuoKGdydBj1b5hKATekbt671I8xQg+b9Zdu1HE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724853982; c=relaxed/simple; bh=RZ7f8KSDfavIg2LMNLDwKSDIUWMWuB94Qd8u4dHZeAw=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=cy6lRP4JgFNNVljK6hdnrzE1nnQMYIR0KccJdUD1/rSNsrOPACylbHIb/fDUlc94FmkEodk1cly7eyixDy6DcBx92XCnj8FNqY54PllJtSgBpfDU1E87aYuFOiVEfg+FpZk06rtXzC9vij0nnjWW+TLenEs7045Yz21mIog+k1g= 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=kSnq8xHZ; arc=none smtp.client-ip=209.85.218.43 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="kSnq8xHZ" Received: by mail-ej1-f43.google.com with SMTP id a640c23a62f3a-a86e9db75b9so235952566b.1 for ; Wed, 28 Aug 2024 07:06:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tuxon.dev; s=google; t=1724853978; x=1725458778; 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=S9iF1jJIvtOjyxkFa1dGcE5P1zK7/0vC9veIHL8v450=; b=kSnq8xHZmThYKL9vBgbC2urulWGAc5YWtqbKicaWc9kVI0opDrqxru4IsLhWzZiRW9 KTpfS/A0KoIa2tR+QG2uJxLyR4PCjK+H7zQvyukTmv7XsaPNqzKj85yYByapooyCXpGd O8dUJJtEpig4t+qZF+pK4GqaCJXezTSw1so2r9MnItWKTuYJ8gvDPnNOypNKs69my8Zg VXsPGIwpk3gNNsw1F2poKM5GLK2kyLU2om44Io95/olJdvmKr7iBAYtmPIrdU19YlAn9 TyWPzQGAKsT/yR5Tvgo51M91dzLw6KU8iLtUI7DsLvPXBTCjTbip6e20Lu2ys8cpc+X8 f9eA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1724853978; x=1725458778; 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=S9iF1jJIvtOjyxkFa1dGcE5P1zK7/0vC9veIHL8v450=; b=nwIsHTLvLcsydBrn52xFftRZXSAZ8EjZE+eMxJ4mWKIQuaKpELMlqomAgLck3cMqWB NtOtjIdDA7wDt6nqw+CxWf355M9BjUilAbIEg53z3uuR51OYeWL1tPnZljkWiVtQujsr 530KmbyMpdQfrem+7cKyNZviPjGzGQrUQE/0ZkcGNV4VItkDFbl0VMo37VuwFG3Eb4hd 4CdAoEVIt3l3diCWTWhJs+C1P4fEDYX8xtfy9a7YHNgxSNYHDsnIOMPDI7OwNulGyduK D4g/9pHbP9T6m+C/0r5x7x0ri1mNkep/tb3uqgf3nRgeXLv7K+70K54gbcjeakdxgYon 8K0Q== X-Forwarded-Encrypted: i=1; AJvYcCVwOAcOwOoOB5/VPVdf3wA2Q2ro7SbAlWGFuvwlMeiItmx68xL85cnKB9NFctSeM2c/BoEJqVPfXQ==@vger.kernel.org X-Gm-Message-State: AOJu0YzizhjLugD0lpjqgqRIHybnXNKo7jgfw1i3hW0rav0gqUiIKi04 H3MaKfzB0Rdn9ramhC3qjw9sSKov600qibPguZn5PX5d6DqTBck0OXbAhakqgSM= X-Google-Smtp-Source: AGHT+IEsHCbcGPRfjvRa3ReFX+yeEg97TxBu8qrzEnpYz3gK7FeIv1FbQkePSMHvE/KzGYp7D32IZw== X-Received: by 2002:a17:907:ea1:b0:a86:789c:2d07 with SMTP id a640c23a62f3a-a86a516305emr1476874566b.4.1724853977604; Wed, 28 Aug 2024 07:06:17 -0700 (PDT) Received: from claudiu-X670E-Pro-RS.. ([82.78.167.144]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a86e54b50dbsm251875666b.93.2024.08.28.07.06.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Aug 2024 07:06:17 -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 v2 3/3] watchdog: rzg2l_wdt: Power on the watchdog domain in the restart handler Date: Wed, 28 Aug 2024 17:06:02 +0300 Message-Id: <20240828140602.1006438-4-claudiu.beznea.uj@bp.renesas.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240828140602.1006438-1-claudiu.beznea.uj@bp.renesas.com> References: <20240828140602.1006438-1-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 for RZ/G3S with old device trees and the rest of the SoCs that use 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. Acked-by: Guenter Roeck Signed-off-by: Claudiu Beznea Reviewed-by: Ulf Hansson --- Changes in v2: - adjusted patch description and comment from code - collected tags Changes since RFC: - use pm_runtime_resume_and_get() and pm_runtime_irq_safe() - drop clock prepare in probe drivers/watchdog/rzg2l_wdt.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c index 2a35f890a288..11bbe48160ec 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 +167,22 @@ 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 SoCs not registering a watchdog IRQ safe power + * domain 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 +290,7 @@ 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;