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: 13665658 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 A9149C25B77 for ; Thu, 16 May 2024 01:22:52 +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=3Aj6YLQjEkHxwFrIAzkWv7F4NOCbJSJeC7ylcLS5hhY=; b=vam6XsFmoKQ7SY buW4Ud4X6zKcRfJvhlJITwurLw3XyreZh8DK9Ulwus/Bj/W1EI+oepWZqbcn4cRoZUOo43bEOMLCE CkAreuxEKY1lTdKlLMm8JzXfoLIDosF8Y7B8czxpUFqDW+/iczIVKSMWQlrhrYqHGHoQRcYQHy9OR 0H6J+oqFX8B5ksdIVHT5nnoIeML1aMG4RyQFaNdnJtELt4mxNKt7C8LsY685fuYD0bVJsD2wdtWzg +MFVeVxUwhnJn5Mih9fCu7pFTYBZuDe6LeZIngig8xtEDz4Gp9nBqQsOrr9WPGZ6PXck0iHTdKMGE jV52lxctuQnSV/a5WyBg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1s7PpP-00000003MHF-1f0k; Thu, 16 May 2024 01:22:39 +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 1s7PpL-00000003MGN-3AId for linux-arm-kernel@lists.infradead.org; Thu, 16 May 2024 01:22:37 +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 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 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-20240515_182235_974362_F582A1D7 X-CRM114-Status: GOOD ( 13.85 ) 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. 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);