From patchwork Thu May 16 19:37:40 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 13666510 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 12E76C25B74 for ; Thu, 16 May 2024 19:38:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Date:Subject:Cc :To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=Kxu1NKNX8iD8ZOtPmKobPFCr7R73IlUyLjaP5KZvvjo=; b=m5qcOJOjj821lu KuT0gsDZ47s/oxLcAV9Dec8/eYf/OhfzO81owirB0MUjaB2EtzEweNZBtjwrPzpY2qAz2/3qjCNYI ozlF6BqgQZpX5rWLzJcsMBZp0SyKK1SKy6xE0eBv5EG12VG78IThMvbSe7gIi2gLGJ2k1Aa9Q54DE uwm6WJjysYAv99TlL7wLK3631pG9UIMGR9rOB7kYhK7AqilYovfOLGenKoZ8yFuOXcZKkkW4LZ4gi 3HkC/g5hhcQZKk411MdNqXAAQ9LsXGrxbOvvYm8wS+YJMWlTeg8uwTG2CHWsU04MobAGZlELpQIB5 9OiztnNrSO6P0fhh25hw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1s7gvu-00000005ygf-2rmd; Thu, 16 May 2024 19:38:30 +0000 Received: from phobos.denx.de ([85.214.62.61]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1s7gvl-00000005yee-3kEW for linux-arm-kernel@lists.infradead.org; Thu, 16 May 2024 19:38:26 +0000 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 36DFC883E7; Thu, 16 May 2024 21:38:16 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1715888298; bh=dh7Mqd4f++NHj/N+9IevrvNykG+N8Z8Ls872HqTQVvo=; h=From:To:Cc:Subject:Date:From; b=fAhcsNkDNlZMlACDyGaE206FqUSLIv183j3cMfyOcR2At6R6oKdRd0CUhb+Qno4aY 0HFBEM+N2Hz9hY/Vg8wmonkhCSZHx1hQM4POhGZq5hplreyrfg7qbcYOPHTsvL91Q2 PNdl5zlW/5VqsO8L73UhRPUAEJ3Pb/R2tGfHziDy9bDuEH7gtEKLP+Hz/JY0ym0cbd nmjpavCxpa3vIlsnoNcGTKex/nnB1dmplv6NUtl+Lk2I1mS7L+BypFje/3h21vPCIZ Zbtucmt2htK4inU9NmTqAY0G9ryPdasTliGzTZBxv94sraVGXaaUpa4oKgjdn+AKQj 41DIXw5VrLrIw== From: Marek Vasut To: linux-crypto@vger.kernel.org Cc: Marek Vasut , Gatien Chevallier , =?utf-8?q?Uwe_Kleine-K?= =?utf-8?q?=C3=B6nig?= , Alexandre Torgue , 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 v2 1/2] hwrng: stm32 - use pm_runtime_resume_and_get() Date: Thu, 16 May 2024 21:37:40 +0200 Message-ID: <20240516193757.12458-1-marex@denx.de> X-Mailer: git-send-email 2.43.0 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240516_123822_500919_F841CCCD X-CRM114-Status: GOOD ( 14.06 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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. Acked-by: Gatien Chevallier Signed-off-by: Marek Vasut --- 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 --- V2: Add AB from Gatien --- 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);