From patchwork Thu May 16 01:20:45 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 13665656 X-Patchwork-Delegate: herbert@gondor.apana.org.au Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (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 C353D10E3 for ; Thu, 16 May 2024 01:22:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=85.214.62.61 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715822559; cv=none; b=gi+FbDNhsFz9O/qB1kPzXafVlp/QdgqOzLvniJBsyU2e0KwHdiZFm0tYBj7VgmY3T1gSqZTGGd2sLAMpznehYWdx9uA+oGLLANrNHRALi+pehtBbzJ5tIAum1HjQGlM07LTmJY1LjwqP3zBjzbsHH3EpwyWE6AldEF5jkOrEQ4A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715822559; c=relaxed/simple; bh=KtEJ5nEI0qaRWOfhPnMYfSTZGU5BZ2ozbg5F0AcDMwg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=iIvhbRHvBjsu+HyZW0eKiydnCH8f1mjusbY4Yd2ozohzQYMEOlMHGDqAqTOR5ZvcO3zS99I520Eb3EgkGplktoA+BPKljnXSq3mqKydm01X2uI02r2cfvHa5XbKpa7SssOT/CCXnnoDovqreMMo740Azn/jm5FC+ZS/OJLZuBhw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de; spf=pass smtp.mailfrom=denx.de; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b=sBMpfJkV; arc=none smtp.client-ip=85.214.62.61 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=denx.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=denx.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=denx.de header.i=@denx.de header.b="sBMpfJkV" Received: from tr.lan (ip-86-49-120-218.bb.vodafone.cz [86.49.120.218]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 86F9587DB0; Thu, 16 May 2024 03:22:31 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1715822553; bh=raQZ10l3+cclQ4SOmqVPgMhHjTADA3OYQuPrKD7T/LI=; h=From:To:Cc:Subject:Date:From; b=sBMpfJkVagA4BWlF8Yo2JVJXO2RpSyTQvvn11ziawhRR4U7vzS08f+D771T011jTw GSRdF9Ja/bcV1NrgUkBvtx8nc3ZXLOwb9eMUbd4dkX2GgD/sPRoklnbMsUqxklzrJX VCImGBQB1ruVh+eRtgaImwvPE+YOEvB3ToUgoCUpH7aX6I+Rz7sYuawlPLl2dtkv5R 2AUPMH6LU3RAm+MmiDQMDatlqq6iRKxRTPmqTSiq3J8xRolKK5rQS81J60SAPuQmjz 2eZKPsRkSdnfYKgYYeP3KqfczlNS+GnUkbML2A/izAmPL3bXU0dQS8cyksSeA7XdzM UuiBopPWJHjvw== From: Marek Vasut To: linux-crypto@vger.kernel.org Cc: Marek Vasut , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Alexandre Torgue , Gatien Chevallier , Herbert Xu , Maxime Coquelin , Olivia Mackall , Rob Herring , Yang Yingliang , kernel@dh-electronics.com, linux-arm-kernel@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com Subject: [PATCH 1/2] hwrng: stm32 - use pm_runtime_resume_and_get() Date: Thu, 16 May 2024 03:20:45 +0200 Message-ID: <20240516012210.128307-1-marex@denx.de> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-crypto@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean include/linux/pm_runtime.h pm_runtime_get_sync() description suggests to ... consider using pm_runtime_resume_and_get() instead of it, especially if its return value is checked by the caller, as this is likely to result in cleaner code. This is indeed better, switch to pm_runtime_resume_and_get() which correctly suspends the device again in case of failure. Also add error checking into the RNG driver in case pm_runtime_resume_and_get() does fail, which is currently not done, and it does detect sporadic -EACCES error return after resume, which would otherwise lead to a hang due to register access on un-resumed hardware. Now the read simply errors out and the system does not hang. Signed-off-by: Marek Vasut Acked-by: Gatien Chevallier --- Cc: "Uwe Kleine-König" Cc: Alexandre Torgue Cc: Gatien Chevallier Cc: Herbert Xu Cc: Marek Vasut Cc: Maxime Coquelin Cc: Olivia Mackall Cc: Rob Herring Cc: Yang Yingliang Cc: kernel@dh-electronics.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-crypto@vger.kernel.org Cc: linux-stm32@st-md-mailman.stormreply.com --- drivers/char/hw_random/stm32-rng.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/char/hw_random/stm32-rng.c b/drivers/char/hw_random/stm32-rng.c index 0e903d6e22e30..6dec4adc49853 100644 --- a/drivers/char/hw_random/stm32-rng.c +++ b/drivers/char/hw_random/stm32-rng.c @@ -187,7 +187,9 @@ static int stm32_rng_read(struct hwrng *rng, void *data, size_t max, bool wait) int retval = 0, err = 0; u32 sr; - pm_runtime_get_sync((struct device *) priv->rng.priv); + retval = pm_runtime_resume_and_get((struct device *)priv->rng.priv); + if (retval) + return retval; if (readl_relaxed(priv->base + RNG_SR) & RNG_SR_SEIS) stm32_rng_conceal_seed_error(rng);